ABSTRACT
This study investigates Symplocos cochinchinensis (Lour.) S. Moore leaves and stems, commonly known as Symplocos, a plant indigenous to Asia renowned for its traditional use in holistic medicine. A comprehensive phytochemical analysis of S. cochinchinensis led to the isolation of two new lignans, namely symplolignans A and B (1 and 2) along with eleven known lignan glucosides: nortrachelogenin 4-O-ß-D-glucopyranoside (3), nortracheloside (4), matairesinol 4-O-ß-D-glucopyranoside (5), lariciresinol 4'-O-ß-D-glucopyranoside (6), balanophonin 4-O-ß-D-glucopyranoside (7), dehydrodiconiferyl alcohol 4-O-ß-D-glucopyranoside (8), dehydrodiconiferyl alcohol γ'-O-ß-D-glucopyranoside (9), 3-(ß-D-glucopyranosyloxymethyl)-2-(4-hydroxy-3-methoxyphenyl)-5-(3-hydroxypropyl)-7-methoxy-(2R,3S)-dihydrobenzofura (10), and pinoresinol 4'-O-ß-D-glucopyranoside (11). Their chemical structures were elucidated using 1D- and 2D-NMR, mass spectrometry, and their spectroscopic data were compared with those reported in literatures. Furthermore, all compounds were evaluated for their hepatoprotective effects using the Resazurin reduction assay in HepG2 hepatocellular carcinoma cells. Compounds 1, 5, 7, and 8 exhibited notable hepatoprotective efficacy, with cell viability ranging from 105.0±2.6 to 109.2±3.3 at a concentration of 10â µM. This research highlights the therapeutic potential of these compounds and enhanced to the understanding of lignans and neolignans in liver cell proliferation.
ABSTRACT
AIM: The initial decrease in estimated glomerular filtration rate (eGFR), often known as the "initial dip," associated with sodium-glucose cotransporter 2 inhibitors (SGLT2i) is typically transient but may be more pronounced in older patients. METHODS: We analyzed real-world data from 2,070 patients newly prescribed SGLT2i, tracking eGFR changes at baseline and 3, 6, 9, and 12 months after initiation. We defined a significant initial dip as over 10 % reduction in eGFR at 3 months. In addition, the 1-year change in eGFR after the initial decline was also assessed. RESULTS: Of the total patients, 34.5 % were aged 60-69 years, 21.1 % were aged 70-79 years, and 11.5 % were aged 80 years or older. About 21.4 % experienced a significant dip at 3 months. The incidence of initial dip increases with age, with the highest incidence (38.7 %) in those aged 80 + . Despite the initial decline, subsequent eGFR was stable over one year in all age groups. Factors such as age, lower hemoglobin, higher uric acid levels, and use of RAS blockers were linked to the initial dip. CONCLUSIONS: Older patients showed a more pronounced initial eGFR decline after starting SGLT2i, but it stabilized for one year without further deterioration, similar to younger patients.
Subject(s)
Diabetes Mellitus, Type 2 , Glomerular Filtration Rate , Sodium-Glucose Transporter 2 Inhibitors , Humans , Sodium-Glucose Transporter 2 Inhibitors/therapeutic use , Glomerular Filtration Rate/drug effects , Aged , Male , Female , Middle Aged , Aged, 80 and over , Diabetes Mellitus, Type 2/drug therapy , Age Factors , Diabetic NephropathiesABSTRACT
Four new acylated oleanane-type triterpene saponins, symplosaponins A-D (1-4) were successfully isolated from the leaves of Symplocos cochinchinensis (Lour.) S. Moore, alongside with five known compounds (5-9), 2-methoxy-4-prop-1-enylphenyl-1-O-ß-D-apiofuranosyl-(1 â 6)-ß-D-glucopyranoside (5), and 1-[O-ß-d-xylopyranosyl-(1 â 6)-O-ß-d-glucopyranosyl]-2,6-dimethoxy-4-propenyl-phenol (6), 6-O-p-coumaroylsucrose (7), arillatose B (8), and (-)-secoisolariciresinol-O-ß-D-glucopyranoside (9). The structures of these compounds were elucidated through spectroscopic methods, comparison with existing data, and chemical methods. Furthermore, all compounds were assessed for their impact on hepatocellular viability using the Resazurin reduction assay. These investigations aimed to explore the potential hepatoprotective properties of isolated compounds. As a result, 1-[O-ß-d-xylopyranosyl-(1 â 6)-O-ß-d-glucopyranosyl]-2,6-dimethoxy-4-propenyl-phenol (6) and (-)-secoisolariciresinol-O-ß-D-glucopyranoside (9) demonstrated statistically significant hepatoprotective activity in a concentration-dependent manner.
Subject(s)
Oleanolic Acid , Phytochemicals , Plant Leaves , Saponins , Saponins/pharmacology , Saponins/isolation & purification , Saponins/chemistry , Molecular Structure , Humans , Plant Leaves/chemistry , Oleanolic Acid/pharmacology , Oleanolic Acid/analogs & derivatives , Oleanolic Acid/isolation & purification , Oleanolic Acid/chemistry , Phytochemicals/pharmacology , Phytochemicals/isolation & purification , Animals , Hep G2 Cells , Rats , Protective Agents/pharmacology , Protective Agents/isolation & purification , Triterpenes/pharmacology , Triterpenes/isolation & purification , Triterpenes/chemistryABSTRACT
Background: Prostate cancer and non-small cell lung cancer (NSCLC) present significant challenges in the development of effective therapeutic strategies. Hormone therapies for prostate cancer target androgen receptors and prostate-specific antigen markers. However, treatment options for prostatic small-cell neuroendocrine carcinoma are limited. NSCLC, on the other hand, is primarily treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors but exhibits resistance. This study explored a novel therapeutic approach by investigating the potential anticancer properties of vitekwangin B, a natural compound derived from Vitex trifolia. Methods: Vitekwangin B was chromatographically isolated from the fruits of V. trifolia. ANO1 protein levels in prostate cancer and NSCLC cells were verified and evaluated again after vitekwangin B treatment. Results: Vitekwangin B did not inhibit anoctamin1 (ANO1) channel function but significantly reduced ANO1 protein levels. These results demonstrate that vitekwangin B effectively inhibited cancer cell viability and induced apoptosis in prostate cancer and NSCLC cells. Moreover, it exhibited minimal toxicity to liver cells and did not affect hERG channel activity, making it a promising candidate for further development as an anticancer drug. Conclusion: Vitekwangin B may offer a new direction for cancer therapy by targeting ANO1 protein, potentially improving treatment outcomes in patients with prostate cancer and NSCLC. Further research is needed to explore its full potential and overcome existing drug resistance challenges.
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Galectin-3 levels have been studied as a potential biomarker for predicting cardiovascular (CV) risk and mortality in hemodialysis (HD) patients. Recently, a close relationship between galectin-3 and vascular calcification (VC) has been reported. Here, we investigated the role of VC as a mediating factor in the association between galectin-3 and mortality. Serum galectin-3 and baseline aortic arch calcification (AoAC) score were measured in 477 incident HD patients. Mortality data were obtained at a median follow-up of 40 months. Causal mediation analysis was performed to examine the effect of vascular risk factors on galectin-3-related mortality. The prevalence of AoAC in HD patients was 57% (n = 272), and elevated galectin-3 levels were associated with a significantly increased risk of AoAC. When the galectin-3 level was divided by the median level of 37 ng/mL, a higher galectin group increased the risk of all-cause mortality by 1.71-fold (95% CI 1.02-2.92, p = 0.048), even after adjustment for multiple CV risk factors. Mediation analysis showed that both the direct effect of the galectin-3 on mortality (ß = 0.0368, bootstrapped 95% CI [0.0113-0.0622]) and the indirect effects were significant. AoAC score and high-sensitivity CRP levels significantly mediated the association between galectin-3 and mortality (total indirect effects: ß = 0.0188, bootstrapped 95% CI [0.0066-0.0352]). This study suggests that the association between high galectin-3 and mortality may be partially mediated by higher VC and inflammatory state in HD patients.
Subject(s)
Galectin 3 , Vascular Calcification , Humans , Galectins , Heart Disease Risk Factors , Renal Dialysis/adverse effectsABSTRACT
BACKGROUND AND AIMS: Methionine adenosyltransferase alpha1 (MATα1) is responsible for the biosynthesis of S-adenosylmethionine in normal liver. Alcohol consumption enhances MATα1 interaction with peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1), which blocks MATα1 mitochondrial targeting, resulting in lower mitochondrial MATα1 content and mitochondrial dysfunction in alcohol-associated liver disease (ALD) in part through upregulation of cytochrome P450 2E1. Conversely, alcohol intake enhances SUMOylation, which enhances cytochrome P450 2E1 expression. MATα1 has potential SUMOylation sites, but whether MATα1 is regulated by SUMOylation in ALD is unknown. Here, we investigated if MATα1 is regulated by SUMOylation and, if so, how it impacts mitochondrial function in ALD. APPROACH AND RESULTS: Proteomics profiling revealed hyper-SUMOylation of MATα1, and prediction software identified lysine 48 (K48) as the potential SUMOylation site in mice (K47 in humans). Experiments with primary hepatocytes, mouse, and human livers revealed that SUMOylation of MAT1α by SUMO2 depleted mitochondrial MATα1. Furthermore, mutation of MATα1 K48 prevented ethanol-induced mitochondrial membrane depolarization, MATα1 depletion, and triglyceride accumulation. Additionally, CRISPR/CRISPR associated protein 9 gene editing of MATα1 at K48 hindered ethanol-induced MATα1-PIN1 interaction, degradation, and phosphorylation of MATα1 in vitro. In vivo, CRISPR/CRISPR associated protein 9 MATα1 K48 gene-edited mice were protected from ethanol-induced fat accumulation, liver injury, MATα1-PIN1 interaction, mitochondrial MATα1 depletion, mitochondrial dysfunction, and low S-adenosylmethionine levels. CONCLUSIONS: Taken together, our findings demonstrate an essential role for SUMOylation of MATα1 K48 for interaction with PIN1 in ALD. Preventing MATα1 K48 SUMOylation may represent a potential treatment strategy for ALD.
Subject(s)
Liver Diseases, Alcoholic , Methionine Adenosyltransferase , Sumoylation , Methionine Adenosyltransferase/metabolism , Methionine Adenosyltransferase/genetics , Animals , Mice , Liver Diseases, Alcoholic/metabolism , Liver Diseases, Alcoholic/etiology , Liver Diseases, Alcoholic/genetics , Humans , Mitochondria, Liver/metabolism , Male , Hepatocytes/metabolism , Liver/metabolismABSTRACT
The importance of vesicular monoamine transporter 2 (VMAT2) in dopamine regulation, which is considered crucial for neuropsychiatric disorders, is currently being studied. Moreover, the development of disease treatments using histone deacetylase (HDAC) inhibitors (HDACi) is actively progressing in various fields. Recently, research on the possibility of regulating neuropsychiatric disorders has been conducted. In this study, we evaluated whether VMAT2 expression increased by an HDACi can fine-tune neuropsychotic behavior, such as attention deficit hyperactivity disorder (ADHD) and protect against the cell toxicity through oxidized dopamine. First, approximately 300 candidate HDACi compounds were added to the SH-SY5Y dopaminergic cell line to identify the possible changes in the VMAT2 expression levels, which were measured using quantitative polymerase chain reaction. The results demonstrated, that treatment with pimelic diphenylamide 106 (TC-H 106), a class I HDACi, increased VMAT2 expression in both the SH-SY5Y cells and mouse brain. The increased VMAT2 expression induced by TC-H 106 alleviated the cytotoxicity attributed to 6-hydroxydopamine (6-OHDA) or 1-methyl-4-phenylpyridinium (MPP+ ) and free dopamine treatment. Moreover, dopamine concentrations, both intracellularly and in the synaptosomes, were significantly elevated by increased VMAT2 expression. These results suggest that dopamine concentration regulation by VMAT2 expression induced by TC-H 106 could alter several related behavioral aspects that was confirmed by attenuation of hyperactivity and impulsivity, which were major characteristics of animal model showing ADHD-like behaviors. These results indicate that HDACi-increased VMAT2 expression offers sufficient protections against dopaminergic cell death induced by oxidative stress. Thus, the epigenetic approach could be considered as therapeutic candidate for neuropsychiatric disease regulation.
Subject(s)
Histone Deacetylase Inhibitors , Neuroblastoma , Humans , Animals , Mice , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylase Inhibitors/therapeutic use , Vesicular Monoamine Transport Proteins/genetics , Cytoprotection , Dopamine , OxidopamineABSTRACT
Anoctamin 1 (ANO1) is a calcium-activated chloride channel found in various cell types and is overexpressed in non-small cell lung cancer (NSCLC), a major cause of cancer-related mortality. With the rising interest in development of druggable compounds for NSCLC, there has been a corresponding rise in interest in ANO1, a novel drug target for NSCLC. However, as ANO1 inhibitors that have been discovered simultaneously exhibit both the functions of an inhibition of ANO1 channel as well as a reduction of ANO1 protein levels, it is unclear which of the two functions directly causes the anticancer effect. In this study, verteporfin, a chemical compound that reduces ANO1 protein levels was identified through high-throughput screening. Verteporfin did not inhibit ANO1-induced chloride secretion but reduced ANO1 protein levels in a dose-dependent manner with an IC50 value of ~300 nM. Moreover, verteporfin inhibited neither P2Y receptor-induced intracellular Ca2+ mobilization nor cystic fibrosis transmembrane conductance regulator (CFTR) channel activity, and molecular docking studies revealed that verteporfin bound to specific sites of ANO1 protein. Confirming that verteporfin reduces ANO1 protein levels, we then investigated the molecular mechanisms involved in its effect on NSCLC cells. Interestingly, verteporfin decreased ANO1 protein levels, the EGFR-STAT3 pathway as well as ANO1 mRNA expression. Verteporfin reduced the viability of ANO1-expressing cells (PC9, and gefitinib-resistant PC9) and induced apoptosis by increasing caspase-3 activity and PARP-1 cleavage. However, it did not affect hERG channel activity. These results show that the anticancer mechanism of verteporfin is caused via the down-regulation of ANO1.
Subject(s)
Anoctamin-1 , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Neoplasm Proteins , Verteporfin , Anoctamin-1/genetics , Anoctamin-1/metabolism , Calcium/metabolism , Carcinoma, Non-Small-Cell Lung/drug therapy , Chloride Channels/metabolism , Down-Regulation , Humans , Lung Neoplasms/drug therapy , Molecular Docking Simulation , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Verteporfin/pharmacologyABSTRACT
PURPOSE: The programmed death protein 1 (PD-1) pathway is the critical mechanism in development of hepatocellular carcinoma (HCC). The present study analyzed the prognostic impact of pretransplant serum soluble PD-1 (sPD-1) concentration and α-FP-des-γ-carboxyprothrombin-tumor volume (ADV) score in patients with previously untreated HCC undergone liver transplantation (LT). METHODS: This retrospective single-center study enrolled 100 patients with HCC who underwent living donor LT from 2010 to 2016. Concentrations of sPD-1 were measured in stored serum samples. RESULTS: Receiver operating characteristic curve analysis of 2-year tumor recurrence resulted in an sPD-1 cutoff of 177.1 µg/mL, which was associated with higher rates of tumor recurrence (P = 0.022), but not with overall patient survival (P = 0.460). The derived cutoff for pretransplant ADV score was 5.4log, which was associated with higher tumor recurrence rate (P < 0.001) and lower overall patient survival rate (P < 0.001). Both sPD-1 of >177.1 µg/mL (hazard ratio [HR], 2.26; P = 0.020) and pretransplant ADV score of >5.4log (HR, 3.56; P < 0.001) were independent risk factors for posttransplant HCC recurrence. The combination of these 2 factors enabled the stratification of patients into 3 groups, with groups having 0, 1, and 2 risk factors differing significantly in the prognosis of tumor recurrence (P < 0.001) and overall patient survival (P = 0.006). CONCLUSION: Both sPD-1 concentration and ADV score have prognostic impacts in patients who underwent LT for untreated HCCs. These factors, both individually and combined, can help in predicting posttransplant prognosis.
ABSTRACT
Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer-related mortality; thus, therapeutic targets continue to be developed. Anoctamin1 (ANO1), a novel drug target considered for the treatment of NSCLC, is a Ca2+-activated chloride channel (CaCC) overexpressed in various carcinomas. It plays an important role in the development of cancer; however, the role of ANO1 in NSCLC is unclear. In this study, diethylstilbestrol (DES) was identified as a selective ANO1 inhibitor using high-throughput screening. We found that DES inhibited yellow fluorescent protein (YFP) fluorescence reduction caused by ANO1 activation but did not inhibit cystic fibrosis transmembrane conductance regulator channel activity or P2Y activation-related cytosolic Ca2+ levels. Additionally, electrophysiological analyses showed that DES significantly reduced ANO1 channel activity, but it more potently reduced ANO1 protein levels. DES also inhibited the viability and migration of PC9 cells via the reduction in ANO1, phospho-ERK1/2, and phospho-EGFR levels. Moreover, DES induced apoptosis by increasing caspase-3 activity and PARP-1 cleavage in PC9 cells, but it did not affect the viability of hepatocytes. These results suggest that ANO1 is a crucial target in the treatment of NSCLC, and DES may be developed as a potential anti-NSCLC therapeutic agent.
Subject(s)
Anoctamin-1/antagonists & inhibitors , Carcinoma, Non-Small-Cell Lung/drug therapy , Diethylstilbestrol/pharmacology , Neoplasm Proteins/antagonists & inhibitors , Anoctamin-1/metabolism , Apoptosis/drug effects , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Diethylstilbestrol/metabolism , Humans , Lung Neoplasms , Neoplasm Proteins/metabolism , Signal TransductionABSTRACT
Cereblon (CRBN), a negative modulator of AMP-activated protein kinase (AMPK), is highly expressed in the retina. We confirmed the expression of CRBN in ARPE-19 human retinal cells by Western blotting. We also demonstrated that CRBN knock-down (KD) could effectively downregulate IL-6 and MCP-1 protein and gene expression in LPS-stimulated ARPE-19 cells. Additionally, CRBN KD increased the phosphorylation of AMPK/acetyl-coenzyme A carboxylase (ACC) and the expression of heme oxygenase-1 (HO-1) in ARPE-19 cells. Furthermore, CRBN KD significantly reduced LPS-induced nuclear translocation of NF-κB p65 and activation of NF-κB promoter activity. However, these processes could be inactivated by compound C (inhibitor of AMPK) and zinc protoporphyrin-1 (ZnPP-1; inhibitor of HO-1). In conclusion, compound C and ZnPP-1 can rescue LPS-induced levels of proinflammatory cytokines (IL-6 and MCP-1) in CRBN KD ARPE-19 cells. Our data demonstrate that CRBN deficiency negatively regulates proinflammatory cytokines via the activation of AMPK/HO-1 in the retina.
ABSTRACT
Olfactory sensing and its modulation are important for the insects in recognizing diverse odors from the environment and in making correct decisions to survive. Identifying new genes involved in olfactory modulation and unveiling their mechanisms may lead us to understand decision making processes in the central nervous system. Here, we report a novel olfactory function of the cyclic nucleotide-gated (CNG) channel CG42260 in modulating ab3A olfactory sensory neurons, which specifically respond to food-derived odors in fruit fly Drosophila melanogaster. We found that two independent CG42260 mutants show reduced responses in the ab3A neurons. Unlike mammalian CNGs, CG42260 is not expressed in the odorant sensory neurons but broadly in the central nervous system including neuropeptide-producing cells. By using molecular genetic tools, we identified CG42260 expression in one pair of neuropeptide F (NPF) positive L1-l cells known to modulate food odor responsiveness. Knockdown of CG42260 in the NPF neurons reduced production of NPF in Ll-1 cells, which in turn, led to reduction of neuronal responses of the ab3A neurons. Our findings show the novel biological function of CG42260 in modulating olfactory responses to food odor through NPF.
Subject(s)
Cyclic Nucleotide-Gated Cation Channels/metabolism , Drosophila melanogaster/physiology , Neuropeptides/metabolism , Olfactory Receptor Neurons/metabolism , Animals , Brain/metabolism , Cyclic Nucleotide-Gated Cation Channels/genetics , Drosophila melanogaster/genetics , Drosophila melanogaster/metabolism , Electrophysiological Phenomena , Mutagenesis, Insertional , Neuropeptides/genetics , Odorants , Smell/physiologyABSTRACT
BACKGROUND: Streptococcus pneumoniae, more than 90 serotypes of which exist, is recognized as an etiologic agent of pneumonia, meningitis, and sepsis associated with significant morbidity and mortality worldwide. Immunization with a pneumococcal pep27 mutant (Δpep27) has been shown to confer comprehensive, long-term protection against even nontypeable strains. However, Δpep27 is effective as a vaccine only after at least three rounds of immunization. Therefore, treatments capable of enhancing the efficiency of Δpep27 immunization should be identified without delay. Panax ginseng Mayer has already been shown to have pharmacological and antioxidant effects. Here, the ability of Korean Red Ginseng (KRG) to enhance the efficacy of Δpep27 immunization was investigated. METHODS: Mice were treated with KRG and immunized with Δpep27 before infection with the pathogenic S. pneumoniae strain D39. Total reactive oxygen species production was measured using lung homogenates, and inducible nitric oxide (NO) synthase and antiapoptotic protein expression was determined by immunoblotting. The phagocytic activity of peritoneal macrophages was also tested after KRG treatment. RESULTS: Compared with the other treatments, KRG significantly increased survival rate after lethal challenge and resulted in faster bacterial clearance via increased phagocytosis. Moreover, KRG enhanced Δpep27 vaccine efficacy by inhibiting reactive oxygen species production, reducing extracellular signal-regulated kinase apoptosis signaling and inflammation. CONCLUSION: Taken together, our results suggest that KRG reduces the time required for immunization with the Δpep27 vaccine by enhancing its efficacy.
ABSTRACT
BACKGROUND: Ginseng has been the subject of many experimental and clinical studies to uncover the diverse biological activities of its constituent compounds. It is a traditional medicine that has been used for its immunostimulatory, antithrombotic, antioxidative, anti-inflammatory, and anticancer effects. Ginseng may interact with concomitant medications and alter metabolism and/or drug transport, which may alter the known efficacy and safety of a drug; thus, the role of ginseng may be controversial when taken with other medications. METHODS: We extensively assessed the effects of Korean Red Ginseng (KRG) in rats on the expression of enzymes responsible for drug metabolism [cytochrome p450 (CYP)] and transporters [multiple drug resistance (MDR) and organic anion transporter (OAT)] in vitro and on the pharmacokinetics of two probe drugs, midazolam and fexofenadine, after a 2-wk repeated administration of KRG at different doses. RESULTS: The results showed that 30 mg/kg KRG significantly increased the expression level of CYP3A11 protein in the liver and 100 mg/kg KRG increased both the mRNA and protein expression of OAT1 in the kidney. Additionally, KRG significantly increased the mRNA and protein expression of OAT1, OAT3, and MDR1 in the liver. Although there were no significant changes in the metabolism of midazolam to its major metabolite, 1'-hydroxymidazolam, KRG significantly decreased the systemic exposure of fexofenadine in a dose-dependent manner. CONCLUSION: Because KRG is used as a health supplement, there is a risk of KRG overdose; thus, a clinical trial of high doses would be useful. The use of KRG in combination with P-glycoprotein substrate drugs should also be carefully monitored.
ABSTRACT
Background: Previous studies have focused on colonization resistance of the gut microbiota against antibiotic resistant strains. However, less research has been performed on respiratory colonization resistance. Methods: Because respiratory colonization is the first step of respiratory infections, intervention to prevent colonization would represent a new approach for preventive and therapeutic measures. The Th17 response plays an important role in clearance of respiratory pathogens. Thus, harnessing the Th17 immune response in the mucosal site would be an effective method to design a respiratory mucosal vaccine. Results: In this study, we show that intranasal Δpep27 immunization induces noncanonical Wnt and subsequent interleukin (IL)-17 secretion, and it inhibits Streptococcus pneumoniae, Staphylococcus aureus, and Klebsiella pneumoniae colonization. Moreover, IL-17A neutralization or nuclear factor of activated T-cell inhibition augmented bacterial colonization, indicating that noncanonical Wnt signaling is involved in pulmonary colonization resistance. Conclusions: Therefore, Δpep27 immunization can provide nonspecific respiratory colonization resistance via noncanonical Wnt signaling and IL-17A-related pathways.
Subject(s)
Interleukin-17/immunology , Lung/immunology , Lung/microbiology , Wnt Signaling Pathway/immunology , Administration, Intranasal/methods , Animals , Antibodies, Bacterial/immunology , Antigens, Bacterial/immunology , Immunization/methods , Klebsiella Infections/immunology , Klebsiella pneumoniae/immunology , Male , Mice , Mice, Inbred BALB C , Pneumococcal Infections/immunology , Pneumococcal Vaccines/immunology , Staphylococcal Infections/immunology , Staphylococcus aureus/immunology , Streptococcus pneumoniae/immunology , Th17 Cells/immunology , Vaccination/methodsABSTRACT
AIMS: Streptococcus pneumoniae infection in acute bacterial meningitis can lead to widespread brain damage and mortality. Inflammatory responses by immune cells in the brain are thought to determine the degree of brain injury. Yet, the mechanisms underlying host responses to pneumococcal meningitis are largely unknown. To explore host responses as a potential therapeutic target for preventing brain injury after pneumococcal meningitis. METHODS: We evaluated signaling mechanisms that minimize neuronal damage caused by pneumococcal infection; specifically, we assessed pathways related to neuronal survival after enhancing estrogen receptor-ß (ER-ß) expression using a natural therapeutic substance known as ginsenoside Rb1 and Rg3 enhanced ginseng. RESULTS: Tissue damage caused by bacterial infection was reduced in Rb1/Rg3-treated mice as a result of microglial activation and the inhibition of apoptosis. Furthermore, Rb1 upregulated the expression of brain-derived neurotrophic factor (BDNF) as well as anti-apoptotic factors including Bcl-2 and Bcl-xL. Using BV2 microglial cells in vitro, Rb1 treatment inhibited microglial apoptosis in a manner associated with JAK2/STAT5 phosphorylation. CONCLUSION: After S. pneumoniae infection in mice, particularly in female mice, Rb1-containing ginseng increased bacterial clearance and survival. These findings inform our understanding of the host immune response to pneumococcal meningitis.
Subject(s)
Brain Injuries/prevention & control , Estrogen Receptor beta/metabolism , Ginsenosides/therapeutic use , Microglia/metabolism , Neuroprotective Agents/therapeutic use , Sex Characteristics , Animals , Apoptosis/drug effects , Brain Injuries/etiology , Brain Injuries/pathology , Cell Line, Transformed , Disease Models, Animal , Estrogen Receptor beta/genetics , Female , Gene Expression Regulation/drug effects , Male , Mice , Mice, Inbred C57BL , Microglia/drug effects , Pneumococcal Infections/complications , Pneumococcal Infections/drug therapy , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Time FactorsABSTRACT
BACKGROUND: Animal olfactory systems detect volatile environmental chemicals and integrate this information to direct the discovery of food and mates as well as danger avoidance. Rather than remaining constant, olfactory response thresholds are modulated by internal and external cues to adapt odor-guided behaviors to changing conditions. RESULTS: Here, we show in Drosophila melanogaster that neuropeptide F (NPF) modulates the responses of a specific population of antennal olfactory sensory neurons (OSNs) to food-derived odors. We show that knock-down of NPF in NPF neurons specifically reduces the responses of the ab3A neurons to ethyl butyrate, a volatile ester found in apples and other fruits. Knock-down of the NPF receptor (NPFR) in the ab3A neuron reduces their responses and disrupts the ability of the flies to locate food. We also identify a sexual dimorphism in ab3A responsiveness: ab3A neurons in females immediately post-eclosion are less responsive to ethyl butyrate than those of both age-matched males and older females. Not only does this change correlate with brain NPF levels, but also NPFR mutants show no such sexual dimorphism. Finally, by way of mechanism, we show that mutation of NPFR seems to cause intracellular clustering of OR22a, the odorant receptor expressed in the ab3A neurons. CONCLUSIONS: Interestingly, this modulation of the peripheral odorant responsiveness of the ab3A neurons by NPF is distinct from the modulation of presynaptic gain in the ab3A neurons previously observed with the similarly named but distinct neuropeptide sNPF. Rather than affecting the strength of the output at the level of the first synapse in the antennal lobe, NPF-NPFR signaling may affect the process of odorant detection itself by causing intracellular OR clustering.
Subject(s)
Butyrates/metabolism , Drosophila Proteins/genetics , Drosophila melanogaster/physiology , Neuropeptides/genetics , Receptors, Neuropeptide/genetics , Receptors, Odorant/genetics , Animals , Drosophila Proteins/metabolism , Drosophila melanogaster/genetics , Female , Food , Male , Neuropeptides/metabolism , Odorants , Olfactory Receptor Neurons/physiology , Receptors, Neuropeptide/metabolism , Receptors, Odorant/metabolismABSTRACT
Although several neural pathways have been implicated in feeding behaviors in mammals [1-7], it remains unclear how the brain coordinates feeding motivations to maintain a constant body weight (BW). Here, we identified a neuropeptide pathway important for the satiety and BW control in Drosophila. Silencing of myoinhibitory peptide (MIP) neurons significantly increased BW through augmented food intake and fat storage. Likewise, the loss-of-function mutation of mip also increased feeding and BW. Suppressing the MIP pathway induced satiated flies to behave like starved ones, with elevated sensitivity toward food. Conversely, activating MIP neurons greatly decreased food intake and BW and markedly blunted the sensitivity of starved flies toward food. Upon terminating the activation protocol of MIP neurons, the decreased BW reverts rapidly to the normal level through a strong feeding rebound, indicating the switch-like role of MIP pathway in feeding. Surprisingly, the MIP-mediated BW decrease occurred independently of sex peptide receptor (SPR), the only known receptor for MIP, suggesting the presence of a yet-unknown MIP receptor. Together, our results reveal a novel anorexigenic pathway that controls satiety in Drosophila and provide a new avenue to study how the brain actively maintains a constant BW.