Taurine attenuates activation of hepatic stellate cells by inhibiting autophagy and inducing ferroptosis.

BACKGROUND: Liver fibrosis is a compensatory response during the tissue repair process in chronic liver injury, and finally leads to liver cirrhosis or even hepatocellular carcinoma. The pathogenesis of hepatic fibrosis is associated with the progressive accumulation of activated hepatic stellate cells (HSCs), which can transdifferentiate into myofibroblasts to produce an excess of the extracellular matrix (ECM). Myofibroblasts are the main source of the excessive ECM responsible for hepatic fibrosis. Therefore, activated hepatic stellate cells (aHSCs), the principal ECM producing cells in the injured liver, are a promising therapeutic target for the treatment of hepatic fibrosis. AIM: To explore the effect of taurine on aHSC proliferation and the mechanisms involved. METHODS: Human HSCs (LX-2) were randomly divided into five groups: Normal control group, platelet-derived growth factor-BB (PDGF-BB) (20 ng/mL) treated group, and low, medium, and high dosage of taurine (10 mmol/L, 50 mmol/L, and 100 mmol/L, respectively) with PDGF-BB (20 ng/mL) treated group. Cell Counting Kit-8 method was performed to evaluate the effect of taurine on the viability of aHSCs. Enzyme-linked immunosorbent assay was used to estimate the effect of taurine on the levels of reactive oxygen species (ROS), malondialdehyde, glutathione, and iron concentration. Transmission electron microscopy was applied to observe the effect of taurine on the autophagosomes and ferroptosis features in aHSCs. Quantitative real-time polymerase chain reaction and Western blot analysis were performed to detect the effect of taurine on the expression of α-SMA, Collagen I, Fibronectin 1, LC3B, ATG5, Beclin 1, PTGS2, SLC7A11, and p62. RESULTS: Taurine promoted the death of aHSCs and reduced the deposition of the ECM. Treatment with taurine could alleviate autophagy in HSCs to inhibit their activation, by decreasing autophagosome formation, downregulating LC3B and Beclin 1 protein expression, and upregulating p62 protein expression. Meanwhile, treatment with taurine triggered ferroptosis and ferritinophagy to eliminate aHSCs characterized by iron overload, lipid ROS accumulation, glutathione depletion, and lipid peroxidation. Furthermore, bioinformatics analysis demonstrated that taurine had a direct targeting effect on nuclear receptor coactivator 4, exhibiting the best average binding affinity of -20.99 kcal/mol. CONCLUSION: Taurine exerts therapeutic effects on liver fibrosis via mechanisms that involve inhibition of autophagy and trigger of ferroptosis and ferritinophagy in HSCs to eliminate aHSCs.

Tumor-suppressive miR-323a inhibits pancreatic cancer cell proliferation and glycolysis through targeting HK-2.

Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 85% of all malignant pancreatic exocrine tumors and is one of the main causes of cancer-related fatalities. PDAC is characterized by a high glycolytic rate to ensure its survival as a result of hypovascularization and the desmoplastic reaction. In this study, microRNA 323a (miR-323a) was shown to be downregulated within pancreatic cancer tissues and cells, and enriched in the glucose metabolism pathway. In vitro, overexpression of miR-323a suppressed cell viability, DNA synthesis, and colony formation; in vivo, miR-323a overexpression suppressed the tumor growth within a xenograft mouse model. Regarding cellular glycolysis, miR-323a overexpression decreased glucose-6-phosphate levels, inhibited glucose uptake, and reduced lactate and adenosine triphosphate production. miR-323a was found to directly target hexokinase 2 (HK-2) and negatively regulated HK-2 expression. HK-2 overexpression exerted oncogenic effects on pancreatic cancer cells and promoted cellular glycolysis; more importantly, HK-2 overexpression partially eliminated the effects of miR-323a overexpression. In conclusion, miR-323a is downregulated within pancreatic cancer and serves as a tumor-suppressive miRNA through inhibiting cancer cell proliferation and glycolysis. miR-323a exerts its tumor-suppressive effects through targeting HK-2.

Integrated 16S rRNA sequencing and metabolomics analysis to investigate the antidepressant role of Yang-Xin-Jie-Yu decoction on microbe-gut-metabolite in chronic unpredictable mild stress-induced depression rat model.

Objectives: Our goals were to evaluate the antidepressant efficacy of Yang-Xin-Jie-Yu Decoction (YXJYD) in Chronic Unpredictable Mild Stress (CUMS)-induced depression rat model and to investigate the underlying mechanisms. Design: We used CUMS-induced depression rat model to evaluate whether oral administration of YXJYD with different doses (2.1 g/kg, 1.05 g/kg and 0.525 g/kg, respectively) improve the depressive-like symptoms, and then performed UHPLC-Q-TOF-MS to explore the active ingredients of YXJYD. Subsequently, rat's cecal contents, serum, and urine were collected from the control group, CUMS model group, and YXJYD high-dose (2.1 g/kg) treatment group. The 16S rRNA sequencing was performed on the cecal contents, based on Illumina MiSeq platform, and ANOVA analysis were used to analyze the composition variety and screen differential expression of gut bacteria in the three groups. 1H Nuclear Magnetic Resonance (NMR) analysis was used for analyzing the metabolites obtained from cecal contents, serum, and urine, and KEGG enrichment analysis was used to identify pathways of differential metabolites. An integrated 16S rRNA sequencing and metabolomic data were conducted to characterize the underlying mechanisms of YXJYD Results: The gut microbial communities, and serum, cecal content, urine metabolic compositions were significantly significantly altered in CUMS-induced depressive rats, while YXJYD effectively ameliorated the CUMS-associated gut microbiota dysbiosis, especially of Monoglobus, and alleviated the disturbance of serum, cecal content, urine metabolome and reversed the changes of key depressive and gut microbiota-related metabolites, such as succinic acid, taurine, hippuric acid, melatonin. With an integrated study of the gut microbiota and metabolomes, we identified the pathway of tricarboxylic acid cycle (TCA cycle) and propanoate metabolism as the regulated target of YXJYD on host-microbiome interaction. Conclusion: Our findings further confirmed the imbalance of metabolism and intestinal microbial is closely related to CUMS-induced depression. YXJYD regulates gut microbiome to affect body metabolomes and then produce antidepressant-like effect in CUMS-induced depressive rats while its molecular mechanism possibly be increased Monoglobus abundance in gut microbiota and regulated the TCA cycle pathway and propanoate metabolism in host.

Total Flavonoids in Premna Fulva Craib Alleviates Brain Neurological Impairment and Influences Nrf2 and HO-1 Expressions in Rats with Ischemia-Reperfusion.

Total flavonoids in Premna fulva Craib (TFPFC) are a kind of flavonoid compound synthesized via photosynthesis extracted from Premna fulva Craib, which possess a strong anti-oxidative effect. Cerebral Ischemia-Reperfusion refers to the body's damage mainly caused by oxidative stress. This study aims to investigate the alleviating effect of TFPFC on brain neurological impairment and its influences on Nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) expressions in rats with Ischemia-Reperfusion. The rat model of Ischemia-Reperfusion was established, and rats were treated with TFPFC or normal saline. At 24 h after reperfusion, the neurological score, volume of cerebral infarction and cerebral water content were analyzed in different groups. The influences of TFPFC treatment on the proliferative activity and apoptosis of oxygen and glucose deprivation/reoxygenation (OGD/R) neural stem cells were detected via methyl thiazolyl tetrazolium (MTT) assay and flow cytometry. Moreover, the malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were measured to evaluate the oxidative stress effect. The influences of TFPFC treatment on the protein and messenger ribonucleic acid (mRNA) expressions of Nrf2 and HO-1 were analyzed using reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. The TFPFC treatment alleviated the neurological impairment in rats after Ischemia-Reperfusion and reduced the volume of cerebral infarction and cerebral edema status in rats with Ischemia-Reperfusion. TFPFC increased the proliferative activity of OGD/R neural stem cells and decreased damage and apoptosis. In addition, the TFPFC treatment reduced the MDA level, improved the SOD activity, and up-regulated the protein and mRNA expressions of Nrf2 and HO-1. The TFPFC treatment may improve oxidative damage and protect the nervous system through the up-regulation of expressions of transcription factors Nrf2 and HO-1.

Comprehensive Transcriptome Sequencing Analysis of Hirudinaria manillensis in Different Growth Periods.

Medical leeches are widely been used in biochemical and clinical medical studies, helping to restore blood circulation to grafted or severely injured tissue. Mostly, adult leeches are being used in the traditional pharmacopeia, but the gene expression profiling of leeches in different growth periods is not well-reported. So, in this study, we used transcriptome analysis to analyze the comparative gene expression patterns of Hirudinaria manillensis (H. manillensis) in different growth periods, including larval, young, and adult stages. We constructed 24 cDNA libraries from H. manillensis larval, young, and adult stages, and about 54,639,118 sequences were generated, 18,106 mRNA transcripts of which 958 novel mRNAs and 491 lncRNAs were also assembled as well. Furthermore, the results of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that the differentially upregulated genes from the larval to adult stages were enriched in pathways such as cilium, myofibril, contractile fiber, cytoskeleton proteins, dilated cardiomyopathy, adrenergic signaling in cardiomyocytes, etc. Moreover, in the adult stages, a significant increase in the expression of the Hirudin-HM (HIRM2) genes was detected. In addition, our comparative transcriptome profiling data from different growth stages of H. manillensis also identified a large number of DEGs and DElncRNAs which were tentatively found to be associated with the growth of H. manillensis; as it grew, the muscle-related gene expression increased, while the lipid metabolism and need for stimulation and nutrition-related genes decreased. Similarly, the higher expression of HIRM2 might attribute to the high expression of protein disulfide isomerase gene family (PDI) family genes in adulthood, which provides an important clue that why adult leeches rather than young leeches are widely used in clinical therapeutics and traditional Chinese medicine.

Transport of oxytocin to the brain after peripheral administration by membrane-bound or soluble forms of receptors for advanced glycation end-products.

Oxytocin (OT) is a neuropeptide hormone. Single and repetitive administration of OT increases social interaction and maternal behaviour in humans and mammals. Recently, it was found that the receptor for advanced glycation end-products (RAGE) is an OT-binding protein and plays a critical role in the uptake of OT to the brain after peripheral OT administration. Here, we address some unanswered questions on RAGE-dependent OT transport. First, we found that, after intranasal OT administration, the OT concentration increased in the extracellular space of the medial prefrontal cortex (mPFC) of wild-type male mice, as measured by push-pull microperfusion. No increase of OT in the mPFC was observed in RAGE knockout male mice. Second, in a reconstituted in vitro blood-brain barrier system, inclusion of the soluble form of RAGE (endogenous secretory RAGE [esRAGE]), an alternative splicing variant, in the luminal (blood) side had no effect on the transport of OT to the abluminal (brain) chamber. Third, OT concentrations in the cerebrospinal fluid after i.p. OT injection were slightly higher in male mice overexpressing esRAGE (esRAGE transgenic) compared to those in wild-type male mice, although this did not reach statistical significance. Although more extensive confirmation is necessary because of the small number of experiments in the present study, the reported data support the hypothesis that RAGE may be involved in the transport of OT to the mPFC from the circulation. These results suggest that the soluble form of RAGE in the plasma does not function as a decoy in vitro.

Integrative analysis of epigenomics, transcriptomics, and proteomics to identify key targets and pathways of Weining granule for gastric cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Weining granule (WNG) is a "Qi-Enriching and Kidney-Tonifying, Spleen-Reinforcing and Stasis-Removing" formula for gastric cancer (GC). Past research we noted WNG inhibited cell growth and raised apoptosis in GC. However, the underlying mechanism of WNG for GC have yet to be systematically clarified. AIM OF THE STUDY: We sought to characterize the molecular landscape of GC cells in vitro after WNG treated, to identify the molecular targets and pathways that were associated with WNG for inducing the apoptosis of GC cells, and further to clarify underlying molecular mechanism of WNG for GC. MATERIALS AND METHODS: We performed the techniques of RNA sequencing, tandem mass tags (TMT) based quantitative proteomics, and reduced representation bisulfite sequencing (RRBS) in WNG-treated/or untreated SGC-7901 GC cells to gain a comprehensive molecular portrait of WNG treatment. Then we integrated methylomics, transcriptomics, and proteomics data to carry out the bioinformatics analysis, and constructed the protein-protein interaction (PPI) network to identify molecular targets, and to discover the underlying signaling pathways associated with WNG for GC by network analysis. Besides, we verified the candidate target genes by Kaplan-Meier plotter database. RESULTS: We identified 1249 significant differentially expressed genes (DEGs) from RNA expression datasets, 191 significant differentially abunabundant proteins (DAPs) from proteomics datasets, and 8293 significant differentially methylated regions (DMRs) from DNA methylation datasets. GO and KEGG analysis showed DEGs, DAPs, and DMRs enriched in the cancer-related biological processes of calcium signaling pathway, pathways in cancer, metabolic pathways, MAPK signaling pathway, PI3K-Akt signaling pathway, and transcriptional misregulation in cancer. We integrated three profile datasets and performed network analysis to distinguish the hub genes, and finally the genes of SOD2, HMOX1, MMP1, SRXN1, NOTCH1, MAPK14, TXNIP, VEGFA, POLR2F, and HSPA9 were identified. The Kaplan-Meier plotter confirmed that SOD2, MMP1, SRXN1, NOTCH1, MAPK14, TXNIP, VEGFA, and HSPA9 were significantly correlated with OS in GC patients (P < 0.01), while HMOX1 and POLR2F expression were not significantly relevant to survival of GC patients (P > 0.01). CONCLUSIONS: SOD2, MMP1, SRXN1, NOTCH1, MAPK14, TXNIP, VEGFA, and HSPA9 were the predictive pharmaceutical targets of WNG for GC. The anticancer function of WNG was significantly associated with the pathways of focal adhesion pathway, PI3K-Akt signaling pathway, MAPK signaling pathway, and Wnt signaling pathway.

Oxytocin and CD38 in the paraventricular nucleus play a critical role in paternal aggression in mice.

In mammals, the development of healthy offspring requires maternal care. Behavior by lactating mothers toward other individuals is an important component of maternal aggression. However, it is unclear whether fathers display aggression primed by pups (an external factor), and the protection mechanism is poorly understood. To address this question, we examined paternal aggression in the ICR mouse strain. We found that sires exposed to cues from pups and lactating dams showed stronger aggression toward intruders than did sires that were deprived of family cues or exposed to nonlactating mates. c-Fos immunohistochemistry showed that cells in both the paraventricular and supraoptic nuclei (PVN and SON, respectively) in the hypothalamus of sires exposed to any cues were highly activated. However, c-Fos activation in oxytocinergic neurons was increased only in sires exposed to pup cues and solely in the PVN. In Cd38-knockout sires, the presence of pups induced no or reduced parental aggression; however, this phenotype was recovered, that is, aggression increased to the wild-type level, after intraperitoneal administration of oxytocin (OT). Specific c-Fos activation patterns induced by pup cues were not found in the PVN of knockout sires. These results demonstrate that the PVN is one of the primary hypothalamic areas involved in paternal aggression and suggest that a CD38-dependent OT mechanism in oxytocinergic neurons is critical for part of the behavior associated with the protection of offspring by nurturing male mice.

Effect of Traditional Chinese Medicine Injection on Cancer-Related Fatigue: A Meta-Analysis Based on Existing Evidence.

METHODS: We systematically searched randomized controlled studies reported through March 2020 in PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, Web of Science, China Biomedical Literature Database (CBM), the China National Knowledge Infrastructure (CNKI), Wanfang, and VIP databases. Two investigators independently screened the studies according to the predetermined criteria, extracted data, and evaluated the bias risk of the included studies, using RevMan5.3 software. RESULTS: Twelve studies enrolling 1005 participants were included in this systematic review. We found that TCMJ could improve the clinical efficacy of CRF patients (RR = 1.24, 95% CI: 1.05-1.46, P=0.01), ameliorate fatigue status (RR = 1.44, 95% CI: 1.27-1.65, P < 0.00001), and improve quality of life (MD = 8.34, 95% CI: 3.31-13.37, P=0.001), but there was no statistical significance in the fatigue score (MD = -1.10, 95% CI: -2.23-0.04, P=0.06). Referring to the number of adverse events, the safety of TCMJ was good. Subgroup analysis showed that TCMJ could improve clinical efficacy, fatigue, and quality of life in a short time (≤4 weeks). Among them, tonic TCMJ could improve the clinical efficacy. TCMJ had advantages in improving fatigue of lung cancer and gastric cancer. In addition, life quality of lung cancer patients improved significantly. CONCLUSION: Current research evidence showed that TCMJ could improve the clinical efficacy, fatigue status, and life quality of patients with CRF. In addition, we found that TCMJ could improve the clinical efficacy of CRF patients in a short period of time. Tonic TCMJ could improve the clinical efficacy, but heat-clearing TCMJ could not. Life quality and fatigue status of lung cancer patients improved significantly. However, due to the sample size and quality of the included studies, the results of this analysis should be treated with caution. The above conclusions still need to be verified by more large-sample and high-quality randomized controlled trials.

Vascular RAGE transports oxytocin into the brain to elicit its maternal bonding behaviour in mice.

Oxytocin sets the stage for childbirth by initiating uterine contractions, lactation and maternal bonding behaviours. Mice lacking secreted oxcytocin (Oxt -/-, Cd38 -/-) or its receptor (Oxtr -/-) fail to nurture. Normal maternal behaviour is restored by peripheral oxcytocin replacement in Oxt -/- and Cd38 -/-, but not Oxtr -/- mice, implying that circulating oxcytocin crosses the blood-brain barrier. Exogenous oxcytocin also has behavioural effects in humans. However, circulating polypeptides are typically excluded from the brain. We show that oxcytocin is transported into the brain by receptor for advanced glycation end-products (RAGE) on brain capillary endothelial cells. The increases in oxcytocin in the brain which follow exogenous administration are lost in Ager -/- male mice lacking RAGE, and behaviours characteristic to abnormalities in oxcytocin signalling are recapitulated in Ager -/- mice, including deficits in maternal bonding and hyperactivity. Our findings show that RAGE-mediated transport is critical to the behavioural actions of oxcytocin associated with parenting and social bonding.

Protective effect and mechanisms of Weining granule on N-methyl-N'-nitro-N- nitrosoguanidine-induced gastric cancer in rats.

OBJECTIVE: To investigate the protective effect and molecular mechanisms of Weining granule on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric cancer in rats. METHODS: A total of sixty healthy male wistar rats were randomly divided into five groups, including control group (CG), gastric cancer model group (MG), low-dose Weining granule treated group (LWT), medium-dose Weining granule treated group (MWT), and high-dose Weining granule treated group (HWT). Except the control group, the other groups were treated with MNNG to establish a rat model of gastric cancer. Low-dose Weining granule treated group, medium-dose Weining granule treated group, and high-dose Weining granule treated group were fed 9.0, 18.0 and 36.0 g/kg Weining granule, respectively. Histopathologic and molecular biologic technology were adopted to determine the protective effect of Weining granule on MNNG-induced gastric cancer in rats. The pathological changes of gastrointestinal tissue were observed. Meanwhile, the differential expression of proliferation, apoptosis and angiogenesis markers were determined, including proliferating cell nuclear antigen (PCNA), pokemon, cyclin D1, B-cell lymphoma-2 (Bcl-2), caspase-3, phosphatase and tensin homolog (PTEN) and vascular endothelial growth factor (VEGF). RESULTS: After the MNNG treated, the pathological changes of stomach tissue were improved noticeably, including the intestinal metaplasia and atypic hyperplasia. The experiment was completed in 58 rats (96.67%). As compared with gastric cancer model group, the general states of rats were improved significantly after treated with different dose Weining granule. Moreover, treatment with different doses of Weining granule could inhibit the protein and mRNA expression of PCNA, pokemon, cyclin D1, Bcl-2, and VEGF, while increase caspase-3 and PTEN (P < 0.01). CONCLUSION: Weining granule could improve gastric cancer by suppressing cell proliferation, promoting tumor cell apoptosis, and inhibiting angiogenesis.

Comprehensive analysis of differentially expressed profiles of Alzheimer's disease associated circular RNAs in an Alzheimer's disease mouse model.

Circular RNAs (circRNAs), a novel kind of non-coding RNA, have received increasing attention for their involvement in pathogenesis of Alzheimer's disease (AD); however, few studies have reported in the characterization and function of AD associated circRNAs. Here the expression profiles of circRNAs in 5- and 10-month-old SAMP8 mice were identified using circRNA microarray and found that 85 dysregulated circRNAs were observed in 10-month-old SAMP8 versus control mice and 231 circRNAs exhibited differential expression in 10-month-old SAMP8 versus 5-month-old SAMP8. One most significantly dysregulated circRNA, mmu_circRNA_017963, was select for Gene Oncology (GO) and pathway analysis. The results showed that mmu_circRNA_017963 was strongly related with autophagosome assembly, exocytosis, apoptotic process, transport and RNA splicing and highly associated with synaptic vesicle cycle, spliceosome, glycosaminoglycan and SNARE interactions in vesicular transport pathways. Collectively, this study was the first to describe circRNAs expression in different ages of SAMP8 and will contribute to the understanding of the regulatory roles of circRNAs in AD pathogenesis and provide a valuable resource for the diagnosis and therapy of AD.

Upregulated Serum MiR-146b Serves as a Biomarker for Acute Ischemic Stroke.

BACKGROUND/AIMS: Stroke is a major cerebrovascular disease threatening human health and life with high morbidity, disability and mortality. It is aimed to find effective biomarkers for the early diagnosis on stroke. METHODS: The expressions of 17 previously reported stroke-associated miRNAs were measured using quantitative RT-PCR and the expressions of plasma high-sensitivity C reactive protein (hs-CRP) and serum interleukin 6 (IL-6), the pro-inflammation markers in brain injury, were examined using enzyme-linked immunosorbent assay in 128 acute ischemic stroke (AIS) patients and control group. RESULTS: Serum miR-146b expression was significantly increased within 24 hours after stroke onset in patients compared with control group. In addition, the upregulation of serum miR-146b was strong positively correlated with plasma hs-CRP, infarct volume and National Institutes of Health Stroke Scale (NIHSS) score, and moderate positively correlated with serum IL-6 of patients. Importantly, the combination of plasma hs-CRP and serum miR-146b gained a better sensitivity/specificity for prediction of AIS (AUC from 0.782 to 0.863). CONCLUSION: Our preliminary findings suggested that upregulated serum miR-146b in acute ischemic stroke might be a potential biomarker for AIS evaluation.

Oxytocin release via activation of TRPM2 and CD38 in the hypothalamus during hyperthermia in mice: Implication for autism spectrum disorder.

Oxytocin (OT) is a critical molecule for social recognition that mediates social and emotional behaviors. OT is released during stress and acts as an anxiolytic factor. To know the precise molecular mechanisms underlying OT release into the brain during stress is important. It has been reported that intracellular concentrations of free calcium in the hypothalamic neurons are elevated by simultaneous stimulation of cyclic ADP-ribose (cADPR) and heat. We have reported in vitro and in vivo data that supports the idea that release of OT in the brain of male mice is regulated by cADPR and fever in relation to stress conditions. 1) Significantly higher levels of OT release were observed in hypothalamus cultures isolated from subordinate mice in group-housed males compared to dominant males after cage-switch stress; 2) OT concentrations in micro-perfusates at the paraventricular nucleus upon perfusion stimulation with cADPR were enhanced in subordinate mice compared to dominant mice; 3) The OT concentration in the cerebrospinal fluid (CSF) was higher in endotoxin-shock mice with fever compared to controls with no body temperature increase; and 4) In mice exposed to new environmental stress, the CSF OT level transiently increased 5 min after exposure, while the rectal temperature increased from 36.6 °C to 37.8 °C from 5 to 15 min after exposure. In this review, we examine whether or not cADPR and hyperthermia co-regulate hypothalamic OT secretion during social stress through the elevation of intracellular free Ca2+ concentrations involved in CD38-dependent Ca2+ mobilization and TRPM2-dependent Ca2+ influx. Finally, we propose that the interaction between CD38 and TRPM2 seems to be a new mechanism for stress-induced release of OT, which may result in anxiolytic effects for temporal recovery from social impairments in children with autism spectrum disorder during hyperthermia.

Naringenin prevents ischaemic stroke damage via anti-apoptotic and anti-oxidant effects.

Apoptosis and oxidative stress are considered to be the major factors associated with the development and progression of many ischaemic cerebrovascular diseases. Naringenin (NAR) is an abundant flavanone in citrus plants and has been found to exhibit anti-oxidant, anti-carcinogenic and anti-apoptotic effects. This study aimed to investigate the anti-apoptotic and anti-oxidant effects of naringenin on ischaemic stroke. In vitro, cortical neuron cells isolated from the brains of neonatal Sprague-Dawley rats were randomly divided into control, oxygen and glucose deprivation/reperfusion (OGD/Rep), NAR-L, NAR-M and NAR-H groups. MTT and RT-PCR were used for cell proliferation and apoptosis-related proteins analyses. The effects of NAR on the Nrf2 signalling pathway were investigated using transfection approaches. Differences in mitochondrial dysfunction were analyzed by flow cytometry. In vivo, middle cerebral artery occlusion (MCAO) model was prepared and neurological defects and the brain wet/dry (W/D) ratio were assessed and recorded; apoptosis was measured based on the TUNEL assay. Additionally, biochemical indices were detected both in vitro and in vivo. NAR promoted cortical neuron cell proliferation, inhibited apoptosis and oxidative stress, and regulated the localization of Nrf2 protein (P<.05). Furthermore, silencing and overexpression of Nrf2 affected cortical neuron cell proliferation and apoptosis (P<.05). In vivo, NAR could alleviate cerebral oedema, improve neurological defects, and reduce apoptosis and oxidative stress (P<.05). These findings demonstrated that NAR could reduce apoptosis and oxidative stress and that Nrf2 signalling pathway is involved in this regulatory process. NAR has health-promoting properties because of its anti-apoptotic and anti-oxidant effects in cases of ischaemic stroke.

An immunohistochemical, enzymatic, and behavioral study of CD157/BST-1 as a neuroregulator.

BACKGROUND: Recent rodent and human studies provide evidence in support of the fact that CD157, well known as bone marrow stromal cell antigen-1 (BST-1) and a risk factor in Parkinson's disease, also meaningfully acts in the brain as a neuroregulator and affects social behaviors. It has been shown that social behaviors are impaired in CD157 knockout mice without severe motor dysfunction and that CD157/BST1 gene single nucleotide polymorphisms are associated with autism spectrum disorder in humans. However, it is still necessary to determine how this molecule contributes to the brain's physiological and pathophysiological functions. METHODS: To gain fresh insights about the relationship between the presence of CD157 in the brain and its enzymatic activity, and aberrant social behavior, CD157 knockout mice of various ages were tested. RESULTS: CD157 immunoreactivity colocalized with nestin-positive cells and elements in the ventricular zones in E17 embryos. Brain CD157 mRNA levels were high in neonates but low in adults. Weak but distinct immunoreactivity was detected in several areas in the adult brain, including the amygdala. CD157 has little or no base exchange activity, but some ADP-ribosyl cyclase activity, indicating that CD157 formed cyclic ADP-ribose but much less nicotinic acid adenine dinucleotide phosphate, with both mobilizing Ca2+ from intracellular Ca2+ pools. Social avoidance in CD157 knockout mice was rescued by a single intraperitoneal injection of oxytocin. CONCLUSIONS: CD157 may play a role in the embryonic and adult nervous systems. The functional features of CD157 can be explained in part through the production of cyclic ADP-ribose rather than nicotinic acid adenine dinucleotide phosphate. Further experiments are required to elucidate how the embryonic expression of CD157 in neural stem cells contributes to behaviors in adults or to psychiatric symptoms.

Cyclic ADP-Ribose and Heat Regulate Oxytocin Release via CD38 and TRPM2 in the Hypothalamus during Social or Psychological Stress in Mice.

Hypothalamic oxytocin (OT) is released into the brain by cyclic ADP-ribose (cADPR) with or without depolarizing stimulation. Previously, we showed that the intracellular free calcium concentration ([Ca(2+)]i) that seems to trigger OT release can be elevated by ß-NAD(+), cADPR, and ADP in mouse oxytocinergic neurons. As these ß-NAD(+) metabolites activate warm-sensitive TRPM2 cation channels, when the incubation temperature is increased, the [Ca(2+)]i in hypothalamic neurons is elevated. However, it has not been determined whether OT release is facilitated by heat in vitro or hyperthermia in vivo in combination with cADPR. Furthermore, it has not been examined whether CD38 and TRPM2 exert their functions on OT release during stress or stress-induced hyperthermia in relation to the anxiolytic roles and social behaviors of OT under stress conditions. Here, we report that OT release from the isolated hypothalami of male mice in culture was enhanced by extracellular application of cADPR or increasing the incubation temperature from 35°C to 38.5°C, and simultaneous stimulation showed a greater effect. This release was inhibited by a cADPR-dependent ryanodine receptor inhibitor and a nonspecific TRPM2 inhibitor. The facilitated release by heat and cADPR was suppressed in the hypothalamus isolated from CD38 knockout mice and CD38- or TRPM2-knockdown mice. In the course of these experiments, we noted that OT release differed markedly between individual mice under stress with group housing. That is, when male mice received cage-switch stress and eliminated due to their social subclass, significantly higher levels of OT release were found in subordinates compared with ordinates. In mice exposed to anxiety stress in an open field, the cerebrospinal fluid (CSF) OT level increased transiently at 5 min after exposure, and the rectal temperature also increased from 36.6°C to 37.8°C. OT levels in the CSF of mice with lipopolysaccharide-induced fever (+0.8°C) were higher than those of control mice. The TRPM2 mRNA levels and immunoreactivities increased in the subordinate group with cage-switch stress. These results showed that cADPR/CD38 and heat/TRPM2 are co-regulators of OT secretion and suggested that CD38 and TRPM2 are potential therapeutic targets for OT release in psychiatric diseases caused by social stress.

Paternal Retrieval Behavior Regulated by Brain Estrogen Synthetase (Aromatase) in Mouse Sires that Engage in Communicative Interactions with Pairmates.

Parental behaviors involve complex social recognition and memory processes and interactive behavior with children that can greatly facilitate healthy human family life. Fathers play a substantial role in child care in a small but significant number of mammals, including humans. However, the brain mechanism that controls male parental behavior is much less understood than that controlling female parental behavior. Fathers of non-monogamous laboratory ICR mice are an interesting model for examining the factors that influence paternal responsiveness because sires can exhibit maternal-like parental care (retrieval of pups) when separated from their pups along with their pairmates because of olfactory and auditory signals from the dams. Here we tested whether paternal behavior is related to femininity by the aromatization of testosterone. For this purpose, we measured the immunoreactivity of aromatase [cytochrome P450 family 19 (CYP19)], which synthesizes estrogen from androgen, in nine brain regions of the sire. We observed higher levels of aromatase expression in these areas of the sire brain when they engaged in communicative interactions with dams in separate cages. Interestingly, the number of nuclei with aromatase immunoreactivity in sires left together with maternal mates in the home cage after pup-removing was significantly larger than that in sires housed with a whole family. The capacity of sires to retrieve pups was increased following a period of 5 days spent with the pups as a whole family after parturition, whereas the acquisition of this ability was suppressed in sires treated daily with an aromatase inhibitor. The results demonstrate that the dam significantly stimulates aromatase in the male brain and that the presence of the pups has an inhibitory effect on this increase. These results also suggest that brain aromatization regulates the initiation, development, and maintenance of paternal behavior in the ICR male mice.

c-Fos expression in the paternal mouse brain induced by communicative interaction with maternal mates.

BACKGROUND: Appropriate parental care by fathers greatly facilitates health in human family life. Much less is known from animal studies regarding the factors and neural circuitry that affect paternal behavior compared with those affecting maternal behavior. We recently reported that ICR mouse sires displayed maternal-like retrieval behavior when they were separated from pups and caged with their mates (co-housing) because the sires receive communicative interactions via ultrasonic and pheromone signals from the dams. We investigated the brain structures involved in regulating this activity by quantifying c-Fos-immunoreactive cells as neuronal activation markers in the neural pathway of male parental behavior. RESULTS: c-Fos expression in the medial preoptic area (mPOA) was significantly higher in sires that exhibited retrieval behavior (retrievers) than those with no such behavior (non-retrievers). Identical increased expression was found in the mPOA region in the retrievers stimulated by ultrasonic vocalizations or pheromones from their mates. Such increases in expression were not observed in the ventral tegmental area (VTA), nucleus accumbens (NAcc) or ventral palladium (VP). On the following day that we identified the families of the retrievers or non-retrievers, c-Fos expression in neuronal subsets in the mPOA, VTA, NAcc and VP was much higher in the retriever sires when they isolated together with their mates in new cages. This difference was not observed in the singly isolated retriever sires in new cages. The non-retriever sires did not display expression changes in the four brain regions that were assessed. CONCLUSION: The mPOA neurons appeared to be activated by direct communicative interactions with mate dams, including ultrasonic vocalizations and pheromones. The mPOA-VTA-NAcc-VP neural circuit appears to be involved in paternal retrieval behavior.

Pairmate-dependent pup retrieval as parental behavior in male mice.

Appropriate parental care by fathers can greatly facilitate healthy human family life. However, much less is known about paternal behavior in animals compared to those regarding maternal behavior. Previously, we reported that male ICR strain laboratory mice, although not spontaneously parental, can be induced to display maternal-like parental care (pup retrieval) when separated from their pups by signals from the pairmate dam (Liu et al., 2013). This parental behavior by the ICR sires, which are not genetically biparental, is novel and has been designated as pairmate-dependent paternal behavior. However, the factors critical for this paternal behavior are unclear. Here, we report that the pairmate-dependent paternal retrieval behavior is observed especially in the ICR strain and not in C57BL/6 or BALB/c mice. An ICR sire displays retrieval behavior only toward his biological pups. A sire co-housed with an unrelated non-pairing dam in a new environment, under which 38-kHz ultrasonic vocalizations are not detected, does not show parenting behavior. It is important for sires to establish their own home territory (cage) by continuous housing and testing to display retrieval behavior. These results indicated that the ICR sires display distinct paternity, including father-child social interaction, and shed light on parental behavior, although further analyses of paternal care at the neuroendocrinological and neurocircuitry levels are required.