Neural basis of opioid-induced respiratory depression and its rescue.

Opioid-induced respiratory depression (OIRD) causes death following an opioid overdose, yet the neurobiological mechanisms of this process are not well understood. Here, we show that neurons within the lateral parabrachial nucleus that express the µ-opioid receptor (PBL Oprm1 neurons) are involved in OIRD pathogenesis. PBL Oprm1 neuronal activity is tightly correlated with respiratory rate, and this correlation is abolished following morphine injection. Chemogenetic inactivation of PBL Oprm1 neurons mimics OIRD in mice, whereas their chemogenetic activation following morphine injection rescues respiratory rhythms to baseline levels. We identified several excitatory G protein-coupled receptors expressed by PBL Oprm1 neurons and show that agonists for these receptors restore breathing rates in mice experiencing OIRD. Thus, PBL Oprm1 neurons are critical for OIRD pathogenesis, providing a promising therapeutic target for treating OIRD in patients.

The Protective Role of Magnoliae Flos in Preventing Ovotoxicity and Managing Ovarian Function: An In Vitro and In Vivo Study.

Magnoliae Flos (MF) is a medicinal herb widely employed in traditional medicine for relieving sinusitis, allergic rhinitis, headaches, and toothaches. Here, we investigated the potential preventive effects of MF extract (MFE) against 4-vinylcyclohexene diepoxide (VCD)-induced ovotoxicity in ovarian cells and a mouse model of premature ovarian insufficiency (POI). The cytoprotective effects of MFE were assessed using CHO-K1 or COV434 cells. In vivo, B6C3F1 female mice were intraperitoneally injected with VCD for two weeks to induce POI, while MFE was orally administered for four weeks, beginning one week before VCD administration. VCD led to a significant decline in the viabilities of CHO-K1 and COV434 cells and triggered excessive reactive oxygen species (ROS) production and apoptosis specifically in CHO-K1 cells. However, pretreatment with MFE effectively prevented VCD-induced cell death and ROS generation, while also activating the Akt signaling pathway. In vivo, MFE increased relative ovary weights, follicle numbers, and serum estradiol and anti-Müllerian hormone levels versus controls under conditions of ovary failure. Collectively, our results demonstrate that MFE has a preventive effect on VCD-induced ovotoxicity through Akt activation. These results suggest that MFE may have the potential to prevent and manage conditions such as POI and diminished ovarian reserve.

Potential Antioxidant and Anti-Inflammatory Properties of Polyphenolic Compounds from Cirsium japonicum Extract.

Cirsium japonicum is a medicinal plant that has been used due to its beneficial properties. However, extensive information regarding its therapeutic potential is scarce in the scientific literature. The antioxidant and anti-inflammatory potential of polyphenols derived from the Cirsium japonicum extracts (CJE) was systematically analyzed. High-performance liquid chromatography (HPLC) with mass spectrometry (MS) was used to examine the compounds in CJE. A total of six peaks of polyphenol compounds were identified in the extract, and their MS data were also confirmed. These bioactive compounds were subjected to ultrafiltration with LC analysis to assess their potential for targeting cyclooxygenase-2 (COX2) and DPPH. The outcomes showed which primary compounds had the highest affinity for binding both COX2 and DPPH. This suggests that components that showed excellent binding ability to DPPH and COX2 can be considered significant active substances. Additionally, in vitro analysis of CJE was carried out in macrophage cells after inducing inflammation with lipopolysaccharide (LPS). As a result, it downregulated the expression of two critical pro-inflammatory cytokines, COX2 and inducible nitric oxide synthase (iNOS). In addition, we found a solid binding ability through the molecular docking analysis of the selected compounds with inflammatory mediators. In conclusion, we identified polyphenolic compounds in CJE extract and confirmed their potential antioxidant and anti-inflammatory effects. These results may provide primary data for the application of CJE in the food and pharmaceutical industries with further analysis.

AAV-mediated skeletal muscle specific irisin expression does not contribute to weight loss in mice.

Obesity, a chronic disease, significantly increases the risk of various diseases, including diabetes, cardiovascular diseases, and cancers. Exercise is crucial for weight management not only through energy expenditure by muscle activity but also through stimulating the secretion of myokines, which affect various tissues. Irisin, derived from the proteolytic processing of fibronectin type III domain-containing protein 5 (Fndc5), is a well-studied myokine with beneficial effects on metabolism. This study explored the feasibility of adeno-associated virus (AAV)-mediated Fndc5 gene therapy to treat obesity in a mouse model using the AAV-DIO system to express Fndc5 specifically in skeletal muscle, and investigated its anti-obesity effect. Although Fndc5 was specifically expressed in the muscle, no significant impact on body weight under normal chow or high-fat diets was observed, and no change in thermogenic gene expression in inguinal white adipose tissue was detected. Notably, Fndc5 transduction did affect bone metabolism, consistent with previous reports. These findings suggest that AAV-mediated Fndc5 gene therapy may not be an efficient strategy for obesity, contrary to our expectations. Further research is needed to elucidate the complex mechanisms involved in irisin's role in obesity and related disorders.

Non-invasive administration of AAV to target lung parenchymal cells and develop SARS-CoV-2-susceptible mice.

Adeno-associated virus (AAV)-mediated gene delivery holds great promise for gene therapy. However, the non-invasive delivery of AAV for lung tissues has not been adequately established. Here, we revealed that the intratracheal administration of an appropriate amount of AAV2/8 predominantly targets lung tissue. AAV-mediated gene delivery that we used in this study induced the expression of the desired protein in lung parenchymal cells, including alveolar type II cells. We harnessed the technique to develop severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-susceptible mice. Three kinds of immune function-relevant gene knockout (KO) mice were transduced with AAV encoding human angiotensin-converting enzyme 2 (hACE2) and then injected with SARS-CoV-2. Among these mice, type I interferon receptor (IFNAR) KO mice showed increased viral titer in the lungs compared to that in the other KO mice. Moreover, nucleocapsid protein of SARS-CoV-2 and multiple lesions in the trachea and lung were observed in AAV-hACE2-transduced, SARS-CoV-2-infected IFNAR KO mice, indicating the involvement of type I interferon signaling in the protection of SARS-CoV-2. In this study, we demonstrate the ease and rapidness of the intratracheal administration of AAV for targeting lung tissue in mice, and this can be used to study diverse pulmonary diseases.

Cold-induced adaptive thermogenesis is impaired by exposure of Asian sand dust in mice.

Desertification and desert sandstorms caused by the worsening global warming pose increasing risks to human health. In particular, Asian sand dust (ASD) exposure has been related to an increase in mortality and hospital admissions for respiratory diseases. In this study, we investigated the effects of ASD on metabolic tissues in comparison to diesel particulate matter (DPM) that is known to cause adverse health effects. We found that larger lipid droplets were accumulated in the brown adipose tissues (BAT) of ASD-administered but not DPM-administered mice. Thermogenic gene expression was decreased in these mice as well. When ASD-administered mice were exposed to the cold, they failed to maintain their body temperature, suggesting that the ASD administration had led to impairments in cold-induced adaptive thermogenesis. However, impaired thermogenesis was not observed in DPM-administered mice. Furthermore, mice fed a high-fat diet that were chronically administered ASD demonstrated unexplained weight loss, indicating that chronic administration of ASD could be lethal in obese mice. We further identified that ASD-induced lung inflammation was not exacerbated in uncoupling protein 1 knockout mice, whose thermogenic capacity is impaired. Collectively, ASD exposure can impair cold-induced adaptive thermogenic responses in mice and increase the risk of mortality in obese mice.

Results From South Korean 2022 Para Report Card on Physical Activity for Children and Adolescents With Disabilities.

South Korea has developed its first Para Report Card on physical activity (PA) for children and adolescents with disabilities. Five national surveillance databases were used to evaluate PA indicators based on the benchmarks and grading rubric provided by Active Healthy Kids Global Alliance. Report card evaluation committees were invited to grade and assess the results using strengths, weaknesses, opportunities, and threats analysis. Five indicators (overall PA, D+; organized sports and PA, D-; active transportation, D-; physical fitness, D+; and government, A+) and one additional indicator (sleep, C-) were assigned a letter grade. The other five indicators were graded as incomplete. The Para Report Card revealed a significant gap between the behavioral-indicator grades (D- to D+) and the policy-indicator grade (A+), suggesting that government strategies and investment have not yet been translated into behavioral PA among children and adolescents with disabilities.

Physical activity levels, exercise preferences, and exercise barriers in Korean children and adolescents after cancer treatment.

PURPOSE: The purpose of the current study was to explore physical activity (PA) levels, exercise preferences, and perceived barriers to PA in childhood cancer survivors. METHODS: This cross-sectional study surveyed 120 childhood cancer survivors aged 8-18 years from the pediatric oncology center in South Korea between March and August 2017. The modified Exercise & Quality of Life questionnaire, Korea Youth Risk Behavior Web-based Survey, and Godin Leisure-Time Questionnaire were used to assess PA levels, preferences, and exercise barriers. RESULTS: Among 120 participants (72 boys, 48 girls) whose average age at the time of the survey was 14.57 ± 3.00 years and the average age at diagnosis was 8.22 years, the three most common diagnoses were acute leukemia (43.3%), brain tumor (13.3%), and malignant lymphoma (10.8%). Only 16 participants (5%) met the PA recommendations for children (at least 60 min of moderate PA per day). The most preferred sporting activities included soccer, basketball, strengthening exercises, badminton, dance, and taekwondo. They generally had positive attitudes toward exercise, and more than 63% of participants intended to exercise the following month. The five most prevalent perceived barriers to exercise were lack of time, poor health, reluctance to sweat, lack of exercise skills, and no exercise partners. CONCLUSIONS: While most childhood cancer survivors did not meet the PA recommendation, most of them agreed that exercise was beneficial, and they intended to participate in the exercise. Exercise and PA programs should be tailored to the personal health and preferences of childhood cancer survivors.

Association of muscle strength and body mass index with risk factors for metabolic syndrome and its prevalence in Korean adult women.

BACKGROUND: The aim of this study was to investigate the effects of muscle strength and BMI (body Mass Index) on Metabolic syndrome (MetS) risk factors and prevalence in Korean adult women, using data from the Korea National Health and Nutrition Examination Survey. METHODS: A total of 3189 Korean adults women participated in the cross-sectional study. Participants were measured BMI, MetS risk factors including waist-circumference (WC), fasting glucose (FG), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), and handgrip strength as muscle strength. RESULTS: As a result 'high BMI & Low muscle strength', 'low BMI & low muscle strength', and 'high BMI & high muscle strength' groups had a significantly higher prevalence of Mets [OR (Odd ratio): 1.49, 95% CI (confidence interval): 1.01 2.20; OR: 5.77, 95% CI: 4.32 7.17; OR: 10.46, 95% CI: 8.05 13.59] than 'low BMI & high muscle strength' group; and after adjusting smoking, menstruation status, and drinking rate, the OR were 1.07 (95% CI: 0.71-1.61), 4.89 (95% CI: 3.60-6.55), and 7.38 (95% CI: 5.63-9.68), respectively. CONCLUSIONS: These findings indicated that increasing muscle strength and lowering BMI through regular physical activity and exercise are effective methods to reduce the prevalence of risk factors for Mets.

Constitutive release of CPS1 in bile and its role as a protective cytokine during acute liver injury.

Carbamoyl phosphate synthetase-1 (CPS1) is the major mitochondrial urea cycle enzyme in hepatocytes. It is released into mouse and human blood during acute liver injury, where is has a short half-life. The function of CPS1 in blood and the reason for its short half-life in serum are unknown. We show that CPS1 is released normally into mouse and human bile, and pathologically into blood during acute liver injury. Other cytoplasmic and mitochondrial urea cycle enzymes are also found in normal mouse bile. Serum, bile, and purified CPS1 manifest sedimentation properties that overlap with extracellular vesicles, due to the propensity of CPS1 to aggregate despite being released primarily as a soluble protein. During liver injury, CPS1 in blood is rapidly sequestered by monocytes, leading to monocyte M2-polarization and homing to the liver independent of its enzyme activity. Recombinant CPS1 (rCPS1), but not control r-transferrin, increases hepatic macrophage numbers and phagocytic activity. Notably, rCPS1 does not activate hepatic macrophages directly; rather, it activates bone marrow and circulating monocytes that then home to the liver. rCPS1 administration prevents mouse liver damage induced by Fas ligand or acetaminophen, but this protection is absent in macrophage-deficient mice. Moreover, rCPS1 protects from acetaminophen-induced liver injury even when given therapeutically after injury induction. In summary, CPS1 is normally found in bile but is released by hepatocytes into blood upon liver damage. We demonstrate a nonenzymatic function of CPS1 as an antiinflammatory protective cytokine during acute liver injury.

Melatonin Regulates Iron Homeostasis by Inducing Hepcidin Expression in Hepatocytes.

The pineal hormone, melatonin, plays important roles in circadian rhythms and energy metabolism. The hepatic peptide hormone, hepcidin, regulates iron homeostasis by triggering the degradation of ferroportin (FPN), the protein that transfers cellular iron to the blood. However, the role of melatonin in the transcriptional regulation of hepcidin is largely unknown. Here, we showed that melatonin upregulates hepcidin gene expression by enhancing the melatonin receptor 1 (MT1)-mediated c-Jun N-terminal kinase (JNK) activation in hepatocytes. Interestingly, hepcidin gene expression was increased during the dark cycle in the liver of mice, whereas serum iron levels decreased following hepcidin expression. In addition, melatonin significantly induced hepcidin gene expression and secretion, as well as the subsequent FPN degradation in hepatocytes, which resulted in cellular iron accumulation. Melatonin-induced hepcidin expression was significantly decreased by the melatonin receptor antagonist, luzindole, and by the knockdown of MT1. Moreover, melatonin activated JNK signaling and upregulated hepcidin expression, both of which were significantly decreased by SP600125, a specific JNK inhibitor. Chromatin immunoprecipitation analysis showed that luzindole significantly blocked melatonin-induced c-Jun binding to the hepcidin promoter. Finally, melatonin induced hepcidin expression and secretion by activating the JNK-c-Jun pathway in mice, which were reversed by the luzindole treatment. These findings reveal a previously unrecognized role of melatonin in the circadian regulation of hepcidin expression and iron homeostasis.

Clinicopathological Features of BRCA1/2 Mutation-Positive Breast Cancer.

PURPOSE: The BRCA1/2 gene is the most well-known and studied gene associated with hereditary breast cancer. BRCA1/2 genetic testing is widely performed in high-risk patients of hereditary breast cancer in Korea. This study aimed to investigate the clinicopathological characteristics of BRCA1/2 mutation-positive breast cancer patients. METHODS: The clinical data of 188 Korean breast cancer patients who underwent genetic testing of BRCA1/2 mutation between March 2015 and February 2020 at Pusan National University Yangsan Hospital were retrospectively reviewed. The characteristics of breast cancer according to the expression of BRCA1 and BRCA2 mutations were analyzed using the Health Insurance Review and Assessment Service guideline criteria and other clinicopathological factors. RESULTS: The factor associated with BRCA1/2 gene expression was cancer stage, and mutation expression was significantly decreased in stage I compared to stage 0 (p = 0.033; odds ratio [OR], 0.169; 95% confidence interval [CI], 0.033-0.867), and there was a tendency to increase in stage II (p = 0.780; OR, 1.150; 95% CI, 0.432-3.064). BRCA1 was significantly associated with triple-negative breast cancer (TNBC) (p = 0.004; OR, 5.887; 95% CI, 1.778-19.498). Gene expression of BRCA2 was significantly reduced under 40 years of age (p = 0.040; OR, 0.198; 95% CI, 0.042-0.930). There was no difference in disease-free survival (p = 0.900) and overall survival (p = 0.733) between the BRCA1/2 mutation-positive and -negative groups. CONCLUSION: In this study, the clinicopathological characteristics of breast cancer patients with BRCA1/2 gene mutations were identified. BRCA1 gene expression was highly correlated with TNBC. BRCA1/2 mutation did not have a poor prognosis regarding recurrence and death.

Protein arginine methyltransferase-1 stimulates dopaminergic neuronal cell death in a Parkinson's disease model.

Recent studies have revealed that protein arginine methyltransferases (PRMTs) are responsible for diverse neurodegenerative diseases. However, their pathophysiological role in dopaminergic neuronal death in Parkinson's disease (PD) has not been evaluated. In this study, we demonstrated that 1-Methyl-4-phenylpyridinium iodide (MPP+), rotenone and paraquat, which cause dopaminergic neuronal cell death, increased PRMT1 expression in dopaminergic cell line. Dopaminergic neuronal cell death was increased by PRMT1 overexpression. MPP+-induced cell death was attenuated by PRMT1 knockdown. Poly (ADP-ribose) polymerase-1 (PARP1) expression and activity, poly-ADP-ribosylation (PARylation), were elevated by MPP+. Moreover, we found that PRMT1 positively regulates nuclear translocation of apoptosis-inducing factor (AIF). Elevated PRMT1 expression was observed in the substantia nigra pars compacta of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-injected mice. Furthermore, MPTP-induced dopaminergic neuronal death was reduced in PRMT1 haploinsufficient (prmt1+/-) mice. These data suggest that PRMT1 is implicated in PARP1/AIF-mediated dopaminergic neuronal cell death, which might be involved in the pathology of PD. Therefore, our results propose PRMT1 as a new target to develop a potential treatment of PD.

A Prospective Longitudinal Study about Change of Sleep, Anxiety, Depression, and Quality of Life in Each Step of Breast Cancer Patients.

PURPOSE: Quality of sleep (QoS), anxiety, depression, and quality of life (QoL) are common issues among breast cancer patients. Prospective longitudinal studies of QoS, anxiety, depression, and QoL in breast cancer patients are lacking. The aim of this study was to find out whether there is a proper treatment point associated with QoS, anxiety, depression, and QoL during early treatment of breast cancer patients. METHODS: We used 4 self-report questionnaires about QoS, anxiety, depression, and QoL. QoS was measured using the Pittsburgh Sleep Quality Index, anxiety was measured with the Beck Anxiety Inventory, depression was measured with the Beck Depression Inventory, and QoL was measured with the Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form. Patients were assessed at the time of surgery, at the beginning of chemotherapy, and at the end of chemotherapy. Clinicopathological information was collected for analysis. RESULTS: Fifty-two patients were enrolled in this study, and 29 completed 3 self-report questionnaires. QoS, anxiety, and depression showed no differences during the early treatment period. However, QoL changed during that period (p = 0.004). Type of breast surgery (total mastectomy vs. breast-conserving surgery) showed a relationship with QoS during the entire treatment period, but with anxiety only at the time of surgery (p = 0.002). Although the sample size was too small, the total mastectomy group showed better results. CONCLUSION: Breast cancer patients experience sleep disturbance, anxiety, depression, and loss of QoL. During the period of treatment, these do not change significantly, but these symptoms are often overlooked. Providing sufficient explanations about the treatment and prognosis of breast cancer and mental support for breast cancer patients prior to treatment will help to improve patients' QoS, anxiety, depression, and QoL.

Production of recombinant human acid ß-glucosidase with high mannose-type N-glycans in rice gnt1 mutant for potential treatment of Gaucher disease.

Gaucher disease is an inherited metabolic disease caused by genetic acid ß -glucosidase (GBA) deficiency and is currently treated by enzyme replacement therapy. For uptake into macrophages, GBA needs to carry terminal mannose residues on their N-glycans. Knockout mutant rice of N-acetylglucosaminyltransferase-I (gnt1) have a disrupted N-glycan processing pathway and produce only glycoproteins with high mannose residues. In this study, we introduced a gene encoding recombinant human GBA into both wild-type rice (WT) and rice gnt1 calli. Target gene integration and mRNA expression were confirmed by genomic DNA PCR and Northern blotting, respectively. Secreted rhGBAs in culture media from cell lines originating from both WT (WT-GBA) and rice gnt1 (gnt1-GBA) were detected by Western blotting. Each rhGBA was purified by affinity and ion exchange chromatography. In vitro catalytic activity of purified rhGBA was comparable to commercial Chinese hamster ovary cell-derived rhGBA. N-glycans were isolated from WT-GBA and gnt1-GBA and analyzed by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The amounts of high mannose-type N-glycans were highly elevated in gnt1-GBA (100%) compared to WT-GBA (1%).

A Modified Formulation of Sutaehwan Ameliorates Menopausal Anxiety, Depression and Heart Hypertrophy in the VCD-Induced Menopausal Mouse Model.

Sutaehwan (STH) has been used in Korean medicine for the treatment of abortus habitualis such as fetal restlessness in the uterus. Previously, we reported that a modified formulation of STH, Sutaehwan-Gami, has phytoestrogen-like properties in an ovariectomized menopausal rat model. However, the therapeutic effects of STH and the precise mechanisms by which STH affects various menopausal symptoms remain poorly understood. The current study was designed to explore the effects of a modified form of STH on menopausal anxiety, depression and heart hypertrophy and its mechanisms in 4-vinylcyclohexene diepoxide (VCD)-induced menopausal mouse models. VCD-induced menopausal model mice were fed a modified form of STH, which contained water extract of 3 herbs (called STH_KP17001) at a dose of 100 or 300 mg/kg/d or as a positive control, estradiol at a dose of 0.2 mg/kg/d with standard mouse pellets for 13 weeks. The results show that STH_KP17001 significantly restored the VCD-induced weight reduction of uterine and ovary through the phosphorylation of extracellular signal-regulated kinase (ERK) and protein kinase B (AKT) in the uterus and ovary. Moreover, STH_KP17001 showed slight proliferative effects and estrogen receptor α phosphorylation in MCF-7 cells. Treatment with STH_KP17001 reversed VCD-induced anxiety and depression through AMP-activated protein kinase (AMPK) activation and brain-derived neurotrophic factor (BDNF) expression in the cerebral cortex, while improving heart hypertrophy through inactivation of inhibitor of kappaB α (IκBα) in the heart. The results indicate that STH_KP17001 improves menopause-induced anxiety, depression and heart hypertrophy, implying its protective role for the management of menopausal symptoms.

Evaluating the impact of suramin additive on CHO cells producing Fc-fusion protein.

OBJECTIVE: To examine the effects of suramin in CHO cell cultures in terms of the cell culture performance and quality of the Fc-fusion protein. RESULTS: Suramin had positive effects on the CHO cell cultures. The addition of suramin caused an increase in the viable cell density, cell viability, and titer of the Fc-fusion protein. Moreover, suramin had no impact on protein aggregation and enhanced the sialic acid contents of Fc-fusion protein by 1.18-fold. The enhanced sialylation was not caused by the increased nucleotide sugar level but by the inhibition of sialidase activity. The results showed that suramin inhibited apoptosis and had positive impacts on the productivity and quality of Fc-fusion protein. CONCLUSION: The addition of suramin increased the production of Fc-fusion protein and enhanced sialylation when added as a supplement to the media component in CHO cell cultures. This study suggested that suramin could be a beneficial additive during the biological production in terms of the productivity and quality of Fc-fusion protein.

A pilot randomized controlled trial of 6-week combined exercise program on fasting insulin and fitness levels in individuals with spinal cord injury.

PURPOSE: The aim of this randomized controlled trial study was to investigate the effect of combined exercise program on the fasting insulin and fitness levels of people with spinal cord injury (SCI). METHODS: A total of 19 individuals with SCI participated in a combined exercise program consisting of aerobic and resistance exercises for 60 min per day, 3 days per week for 6 weeks. Peak oxygen consumption, body mass index, percent body fat, waist circumference, shoulder abduction and adduction, shoulder flexion and extension, elbow flexion and extension, fasting insulin levels, and homeostasis model assessment of insulin resistance (HOMA-IR) levels were measured at baseline and after the intervention. RESULTS: The 6-week exercise program significantly decreased the average fasting insulin (baseline: 7.5 ± 4.7 µU/ml vs. post-intervention: 4.5 ± 2.2 µU/ml, p < 0.05) and HOMA-IR (baseline: 1.5 ± 1.0 vs. post-intervention: 0.9 ± 0.4, p < 0.05) in the exercise group, whereas there was no change in control group (between group difference, mean fasting insulin: - 3.2 µU/ml, p = 0.003; mean HOMA-IR: - 0.66, p = 0.001). In addition, muscle strength of the shoulder flexors, extensors, abductors, adductors, and elbow flexors was significantly improved in the exercise group compared to the controls. CONCLUSION: A combined exercise program is effective in decreasing fasting insulin and HOMA-IR levels while improving fitness in those with SCI. These slides can be retrieved under Electronic Supplementary Material.

Phosphoinositide 5- and 3-phosphatase activities of a voltage-sensing phosphatase in living cells show identical voltage dependence.

Voltage-sensing phosphatases (VSPs) are homologs of phosphatase and tensin homolog (PTEN), a phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2] and phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3] 3-phosphatase. However, VSPs have a wider range of substrates, cleaving 3-phosphate from PI(3,4)P2 and probably PI(3,4,5)P3 as well as 5-phosphate from phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and PI(3,4,5)P3 in response to membrane depolarization. Recent proposals say these reactions have differing voltage dependence. Using Förster resonance energy transfer probes specific for different PIs in living cells with zebrafish VSP, we quantitate both voltage-dependent 5- and 3-phosphatase subreactions against endogenous substrates. These activities become apparent with different voltage thresholds, voltage sensitivities, and catalytic rates. As an analytical tool, we refine a kinetic model that includes the endogenous pools of phosphoinositides, endogenous phosphatase and kinase reactions connecting them, and four exogenous voltage-dependent 5- and 3-phosphatase subreactions of VSP. We show that apparent voltage threshold differences for seeing effects of the 5- and 3-phosphatase activities in cells are not due to different intrinsic voltage dependence of these reactions. Rather, the reactions have a common voltage dependence, and apparent differences arise only because each VSP subreaction has a different absolute catalytic rate that begins to surpass the respective endogenous enzyme activities at different voltages. For zebrafish VSP, our modeling revealed that 3-phosphatase activity against PI(3,4,5)P3 is 55-fold slower than 5-phosphatase activity against PI(4,5)P2; thus, PI(4,5)P2 generated more slowly from dephosphorylating PI(3,4,5)P3 might never accumulate. When 5-phosphatase activity was counteracted by coexpression of a phosphatidylinositol 4-phosphate 5-kinase, there was accumulation of PI(4,5)P2 in parallel to PI(3,4,5)P3 dephosphorylation, emphasizing that VSPs can cleave the 3-phosphate of PI(3,4,5)P3.

Decursin induces apoptosis in glioblastoma cells, but not in glial cells via a mitochondria-related caspase pathway.

Decursin is a major biological active component of Angelica gigas Nakai and is known to induce apoptosis of metastatic prostatic cancer cells. Recently, other reports have been commissioned to examine the anticancer activities of this plant. In this study, we evaluated the inhibitory activity and related mechanism of action of decursin against glioblastoma cell line. Decursin demonstrated cytotoxic effects on U87 and C6 glioma cells in a dose-dependent manner but not in primary glial cells. Additionally, decursin increased apoptotic bodies and phosphorylated JNK and p38 in U87 cells. Decursin also down-regulated Bcl-2 as well as cell cycle dependent proteins, CDK-4 and cyclin D1. Furthermore, decursin-induced apoptosis was dependent on the caspase activation in U87 cells. Taken together, our data provide the evidence that decursin induces apoptosis in glioblastoma cells, making it a potential candidate as a chemotherapeutic drug against brain tumor.