ABSTRACT
L-arginine, as an essential substance of the immune system, plays a vital role in innate immunity. MiR155, a multi-functional microRNA, has gained importance as a regulator of homeostasis in immune cells. However, the immunoregulatory mechanism between L-arginine and miR155 in bacterial infections is unknown. Here, we investigated the potential role of miR155 in inflammation and the molecular regulatory mechanisms of L-arginine in Streptococcus uberis (S. uberis) infections. And we observed that miR155 was up-regulated after infection, accompanying the depletion of L-arginine, leading to metabolic disorders of amino acids and severe tissue damage. Mechanically, the upregulated miR155 mediated by the p65 protein played a pro-inflammatory role by suppressing the suppressor of cytokine signaling 6 (SOCS6)-mediated p65 ubiquitination and degradation. This culminated in a violently inflammatory response and tissue damage. Interestingly, a significant anti-inflammatory effect was revealed in L-arginine supplementation by reducing miR155 production via inhibiting p65. This work firstly uncovers the pro-inflammatory role of miR155 and an anti-inflammatory mechanism of L-arginine in S.uberis infection with a mouse mastitis model. Collectively, we provide new insights and strategies for the prevention and control of this important pathogen, which is of great significance for ensuring human food health and safety.
Subject(s)
Arginine , Mastitis , MicroRNAs , Streptococcal Infections , Animals , Female , Humans , Mice , Arginine/metabolism , Inflammation/metabolism , MicroRNAs/genetics , Streptococcal Infections/metabolism , Streptococcus/physiology , Suppressor of Cytokine Signaling Proteins/metabolism , Mastitis/immunology , Mastitis/metabolismABSTRACT
OBJECTIVE: Pathological destruction of insulin signaling molecules such as insulin receptor substrate, especially due to the increase in suppressors of cytokine signaling molecules, has been demonstrated in experimental diabetes. The contribution of suppressors of cytokine signaling proteins to the development of insulin resistance and the effects of antidiabetic drugs and exercise on suppressors of cytokine signaling proteins are not clearly known. METHODS: A total of 48 Wistar albino adult male rats were divided into six groups: control group, obese group with diabetes, obese diabetic rats treated with metformin, obese diabetic rats treated with pioglitazone, obese diabetic rats treated with exenatide, and obese diabetic rats with applied exercise program. Immunohistochemical staining was performed in both the liver and adipose tissue. RESULTS: There was a statistically significant decrease in suppressors of cytokine signaling-1, a decrease in suppressors of cytokine signaling-3, an increase in insulin receptor substrate-1, and a decrease in immunohistochemical staining in the obese group treated with metformin and exenatide compared to the obese group without treatment in the liver tissue (p<0.05). A statistically significant decrease in immunohistochemical staining of suppressors of cytokine signaling-1 and suppressors of cytokine signaling-3 was found in the obese group receiving exercise therapy compared to the obese group without treatment in visceral adipose tissue (p<0.05). Likewise, no significant immunohistochemistry staining was seen in diabetic obese groups. CONCLUSION: Metformin or exenatide treatment could prevent the degradation of insulin receptor substrate-1 protein by reducing the effect of suppressors of cytokine signaling-1 and suppressors of cytokine signaling-3 proteins, especially in the liver tissue. In addition, exercise can play a role as a complementary therapy by reducing suppressors of cytokine signaling-1 and suppressors of cytokine signaling-3 proteins in visceral adipose tissue.
Subject(s)
Diabetes Mellitus, Experimental , Insulin Resistance , Metformin , Animals , Humans , Male , Rats , Cytokines/metabolism , Exenatide/metabolism , Exercise Therapy , Hypoglycemic Agents , Insulin/metabolism , Insulin Receptor Substrate Proteins/metabolism , Obesity/metabolism , Rats, Wistar , Suppressor of Cytokine Signaling Proteins/metabolismABSTRACT
BACKGROUND: The significant clinical efficacy of Xuanfei Baidu Decoction (XFBD) is proven in the treatment of patients with coronavirus disease 2019 (COVID-19) in China. However, the mechanisms of XFBD against acute lung injury (ALI) are still poorly understood. METHODS: In vivo, the mouse model of ALI was induced by IgG immune complexes (IgG-IC), and then XFBD (4g/kg, 8g/kg) were administered by gavage respectively. 24 h after inducing ALI, the lungs were collected for histological and molecular analysis. In vitro, alveolar macrophages inflammation models induced by IgG-IC were performed and treated with different dosage of XFBD-containing serum to investigate the protective role and molecular mechanisms of XFBD. RESULTS: The results revealed that XFBD mitigated lung injury and significantly downregulated the production of pro-inflammatory mediators in lung tissues and macrophages upon IgG-IC stimulation. Notably, XFBD attenuated C3a and C5a generation, inhibited the expression of C3aR and C5aR and suppressed the activation of JAK2/STAT3/SOCS3 and NF-κB signaling pathway in lung tissues and macrophages induced by IgG-IC. Moreover, in vitro experiments, we verified that Colivelin TFA (CAF, STAT3 activator) and C5a treatment markedly elevated the IgG-IC-triggered inflammatory responses in macrophages and XFBD weakened the effects of CAF or C5a. CONCLUSION: XFBD suppressed complement overactivation and ameliorated IgG immune complex-induced acute lung injury by inhibiting JAK2/STAT3/SOCS3 and NF-κB signaling pathway. These data contribute to understanding the mechanisms of XFBD in COVID-19 treatment.
Subject(s)
Acute Lung Injury , COVID-19 , Animals , Humans , Mice , Acute Lung Injury/drug therapy , Acute Lung Injury/metabolism , Antigen-Antibody Complex/metabolism , COVID-19/pathology , COVID-19 Drug Treatment , Immunoglobulin G , Janus Kinase 2/metabolism , Lipopolysaccharides , Lung/pathology , NF-kappa B/metabolism , Signal Transduction , Suppressor of Cytokine Signaling 3 Protein/metabolism , Suppressor of Cytokine Signaling Proteins/metabolismABSTRACT
Leptin receptors (LepR) are expressed in brain areas controlling food intake homeostasis, such as the hypothalamus, the hippocampus and the prefrontal cortex. In a previous study we reported that long-term intake of saturated and monounsaturated fat alters hypothalamic LepR signalling. The current study aims at investigating the effect of foods high in either saturated (SOLF) or monounsaturated fat (UOLF) on LepR functionality in the hippocampus and the prefrontal cortex. Male mice were placed on SOLF/UOLF (eight weeks), then treated with recombinant murine leptin (1 mg/kg). After 60 min, brain regions were dissected and processed for western blot of phosphorylated STAT3 (pSTAT3), Akt (pAkt) and AMPK (pAMPK). Levels of SOCS3 were also quantified. SOLF itself increased basal levels of pSTAT3, while UOLF impaired leptin-induced phosphorylation of both Akt and AMPK. SOCS3 levels were specifically increased by UOLF within the prefrontal cortex. Our results show that SOLF and UOLF differently affect LepR signalling within the hippocampus and the prefrontal cortex, which points to the complex effect of saturated and unsaturated fat on brain function, particularly in areas regulating food intake.
Subject(s)
Brain , Receptors, Leptin , Animals , Male , Mice , AMP-Activated Protein Kinases , Brain/metabolism , Fats, Unsaturated/administration & dosage , Hypothalamus/metabolism , Leptin/metabolism , Proto-Oncogene Proteins c-akt , Receptors, Leptin/metabolism , Suppressor of Cytokine Signaling Proteins/metabolismABSTRACT
Börjeson-Forssman-Lehmann syndrome (BFLS) is an intellectual disability and endocrine disorder caused by plant homeodomain finger 6 (PHF6) mutations. Individuals with BFLS present with short stature. We report a mouse model of BFLS, in which deletion of Phf6 causes a proportional reduction in body size compared with control mice. Growth hormone (GH) levels were reduced in the absence of PHF6. Phf6-/Y animals displayed a reduction in the expression of the genes encoding GH-releasing hormone (GHRH) in the brain, GH in the pituitary gland and insulin-like growth factor 1 (IGF1) in the liver. Phf6 deletion specifically in the nervous system caused a proportional growth defect, indicating a neuroendocrine contribution to the phenotype. Loss of suppressor of cytokine signaling 2 (SOCS2), a negative regulator of growth hormone signaling partially rescued body size, supporting a reversible deficiency in GH signaling. These results demonstrate that PHF6 regulates the GHRH/GH/IGF1 axis.
Subject(s)
Down-Regulation , Epilepsy/metabolism , Face/abnormalities , Fingers/abnormalities , Growth Disorders/metabolism , Growth Hormone-Releasing Hormone/metabolism , Growth Hormone/metabolism , Hypogonadism/metabolism , Insulin-Like Growth Factor I/metabolism , Mental Retardation, X-Linked/metabolism , Obesity/metabolism , Repressor Proteins/metabolism , Signal Transduction , Animals , Animals, Newborn , Disease Models, Animal , Epilepsy/blood , Epilepsy/pathology , Face/pathology , Fingers/pathology , Growth Disorders/blood , Growth Disorders/pathology , Growth Hormone/blood , Hypogonadism/blood , Hypogonadism/pathology , Hypothalamus/metabolism , Insulin-Like Growth Factor I/genetics , Male , Mental Retardation, X-Linked/blood , Mental Retardation, X-Linked/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , Nervous System/metabolism , Obesity/blood , Obesity/pathology , Organ Specificity , Pituitary Gland/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Suppressor of Cytokine Signaling Proteins/metabolismABSTRACT
The aim of this study was to analyse changes in the abundance of prolactin (PRL) receptor (PRLR) and suppressor of cytokine signalling-3 (SOCS-3) mRNA in the ventro-/dorsomedial nucleus (VMH/DMH) and arcuate nucleus (ARC) of the hypothalamus as well as in the median eminence (ME) and adenohypophysis (AP) in sheep at 30, 60, 90 and 120 d of pregnancy compared to non-pregnant animals. In the VMH/DMH, PRLR transcripts were detected only in non-pregnant ewes. In the ARC, the abundances of PRLR mRNA were higher in pregnant sheep on days 30 (p < .01), 90 (p < .01) and 120 (p < .05) than in non-pregnant sheep. In contrast, the expression of PRLR mRNA in the ME was lower (p < .01) in pregnant ewes at days 30 and 60 than in non-pregnant ewes and was undetectable at later stages of gestation. In all studied stages of pregnancy except day 60, the abundance of PRLR mRNA was higher (p < .01) in the ARC than in the AP, while in non-pregnant sheep, there were no differences (p ≥ .05) in the transcript levels between these two tissues. In non-pregnant ewes, the abundance of SOCS-3 mRNA in the AP was lower than that in any other studied tissue (p < .05-p < .01). In conclusion, the observed changes in PRLR and SOCS-3 mRNA abundance in the hypothalamus and AP during pregnancy may be important components of the mechanisms regulating the action of PRL in energy homeostasis and neuroendocrine interactions within the hypothalamic-pituitary axis.
Subject(s)
Hypothalamus/metabolism , Pituitary Gland, Anterior/metabolism , Pregnancy/metabolism , Receptors, Prolactin/metabolism , Suppressor of Cytokine Signaling Proteins/metabolism , Animals , Female , Gene Expression Profiling , Pregnancy/genetics , RNA, Messenger/metabolism , Receptors, Prolactin/genetics , Sheep, Domestic/genetics , Sheep, Domestic/metabolism , Suppressor of Cytokine Signaling Proteins/geneticsABSTRACT
Intraperitoneal adhesion is a common complication after abdominal surgery, which seriously affects the quality of life of patients. HuoXueTongFu Formula (HXTF) plays an important role in the prevention and treatment of intraperitoneal adhesions. However, the molecular-related mechanisms are still not fully known. In this study, the model of Intrapetitoneal adhesion was established by cecum abrasion and treated with HXTF for one week. RAW264.7 cells were given LPS, IFN-γ, IL-4, HXTF-medicated serum, and PPAR-γ agonist/antagonist, respectively. Histopathology, flow cytometry, ELISA, real-time PCR, and Western blotting were used to further detect the related protein, M1/M2 polarization tendency, and PPAR-γ nuclear translocation. The deposition of collagen fibres reduced in the local area of rats after the operation with HXTF treatment. Similar to IL-4, HXTF induced a tendency for macrophages to polarize toward M2 and promoted peroxisome proliferator-activated receptor-gamma (PPAR-γ) nuclear translocation. Furthermore, the use of HXTF and PPAR-γ agonists downregulated macrophage M1 polarization-related factors IL-1, IL-6, and TNF-alpha and upregulated M2 polarization-related factors IL-4, IL-10, and TGF-beta 1. Meanwhile, the use of HXTF and PPAR-γ agonists downregulated the SOCS3/JAK2/STAT1 pathway and activated the SOCS1/STAT6/PPAR-γ pathway. These results show that HXTF may reduce intraperitoneal adhesion by inducing macrophage M2 polarization and regulating the SOCS/JAK2/STAT/PPAR-γ pathway.
Subject(s)
Janus Kinase 2/metabolism , Macrophages/metabolism , PPAR gamma/metabolism , Plant Extracts/pharmacology , STAT1 Transcription Factor/metabolism , Suppressor of Cytokine Signaling Proteins/metabolism , Animals , Blotting, Western , Cell Polarity/drug effects , Cell Survival/drug effects , Flow Cytometry , Interferon-gamma/metabolism , Interleukin-10/metabolism , Interleukin-4/metabolism , Macrophage Activation/drug effects , Macrophages/drug effects , Male , Mice , Quality of Life , RAW 264.7 Cells , Random Allocation , Rats , Rats, Sprague-Dawley , Real-Time Polymerase Chain Reaction , Signal Transduction/drug effectsABSTRACT
BACKGROUND: Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) is a well-known treatment for non-hypertrophic actinic keratoses and superficial basal-cell carcinomas. OBJECTIVES: In this study, we first revealed that ALA-PDT treatment effectively ameliorated the psoriasis-like lesion in imiquimod (IMQ)-induced mouse model and further explored the potential molecular mechanism and related signalling pathways during the treatment. Besides, we also confirmed a significant alleviation of ALA-PDT therapy on IFN-γ-induced over-proliferation of keratinocytes. METHODS: H&E staining was conducted to reveal the histological changes of mice in different groups. The different expression levels of RNA were illustrated by using QRT-PCR. Western blot was performed to confirm the various expression levels of protein in mice. In vitro, cell proliferation and cell cycle were evaluated by cell counting kit-8 and flow cytometry assay, respectively. RESULTS: The result showed that ALA-PDT's anti-proliferation effect and regulation on Socs1/3, JAK1/2 and K17 in IFN-γ-induced keratinocytes were largely weakened by NAC, indicating that ALA-PDT attenuated the proliferation of IFN-γ-induced keratinocytes by enhancing ROS level. CONCLUSIONS: These results demonstrated that ALA-PDT largely activated the productivity of Socs1/3 in a ROS-dependent manner. Socs1/3 is a potential blocker in JAK signalling pathway and inhibits the proliferation and keratinization of keratinocytes in psoriasis.
Subject(s)
Aminolevulinic Acid/pharmacology , Janus Kinases/metabolism , Photochemotherapy , Photosensitizing Agents/pharmacology , Psoriasis/drug therapy , Animals , Drug Evaluation, Preclinical , Female , Imiquimod , Interferon-gamma , Keratinocytes/drug effects , Mice, Inbred BALB C , Psoriasis/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Suppressor of Cytokine Signaling Proteins/metabolismABSTRACT
Non-small cell lung cancer (NSCLC) is one of the most common aggressive malignancies. miRNAs have been identified as important biomarkers and regulators of NSCLC. However, the functional contributions of miR-1260b to NSCLC cell proliferation and apoptosis have not been studied. In this study, miR-1260b was upregulated in NSCLC plasma, tissues, and cell lines, and its high expression was correlated with tumor size and progression. Functionally, miR-1260b overexpression promoted cell proliferation and cell cycle, conversely inhibited cell apoptosis and senescence. Mechanically, miR-1260b negatively regulated SOCS6 by directly binding to its 3'-UTR. Furthermore, miR-1260b-mediated suppression of SOCS6 activated KIT signaling. Moreover, YY1 was an upstream regulator of miR-1260b. This study is the first to illustrate that miR-1260b, mediated by YY1, activates KIT signaling by targeting SOCS6 to regulate NSCLC cell proliferation and apoptosis, and is a potential biomarker and therapeutic target for NSCLC. In sum, our work provides new insights into the molecular mechanisms of NSCLC involved in cell proliferation and apoptosis.
Subject(s)
Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/metabolism , MicroRNAs/metabolism , Proto-Oncogene Proteins c-kit/metabolism , Suppressor of Cytokine Signaling Proteins/metabolism , YY1 Transcription Factor/metabolism , Apoptosis/physiology , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Proliferation/physiology , Humans , Lung Neoplasms/genetics , Lung Neoplasms/pathology , MicroRNAs/genetics , Proto-Oncogene Proteins c-kit/genetics , Signal Transduction , Suppressor of Cytokine Signaling Proteins/genetics , Transfection , Up-Regulation , YY1 Transcription Factor/geneticsABSTRACT
BACKGROUND: Osthole has been widely reported to have pharmacological activities such as anti-cancer, anti-inflammation and anti-hyperlipidemic effects. Klotho was identified as an anti-senescence protein in a variety of tissues. Loss of klotho has been associated with chronic kidney disease. However, potential roles and molecular events for osthole and klotho in diabetic nephropathy remain unclear. PURPOSE: In the current study, we undertook to study the effect of osthole on klotho expression in advanced glycation end products (AGE)-cultured human renal proximal tubular cells, and to investigate the molecular mechanisms of osthole and exogenous klotho against AGE-induced renal tubular hypertrophy. METHODS: Cell viability was elucidated by MTT assay. Protein expression was measured by Western blotting. mRNA level was analyzed by real-time PCR. Cellular hypertrophy growth was evaluated by hypertrophy index. Relative cell size was detected by flow cytometry. RESULTS: We found that raising the ambient AGE concentration causes a dose-dependent decrease in klotho synthesis. Osthole significantly increased AGE-inhibited klotho mRNA and protein expression. Osthole and exogenous klotho treatments significantly attenuated AGE-induced Janus kinase 2 (JAK2)-signal transducers and activators of transcription 1 (STAT1) and STAT3 activation. Moreover, protein levels of suppressor of cytokine signaling 1 (SOCS1) and SOCS3 were augmented by osthole and exogenous klotho. The abilities of osthole and exogenous klotho to reverse AGE-induced cellular hypertrophy were verified by the observation that osthole and exogenous klotho inhibited p21Waf1/Cip1/collagen IV/RAGE expression, total protein content, and cell size. CONCLUSION: Consequently, we found that osthole attenuated AGE-induced renal tubular hypertrophy via induction of klotho expression and suppression of the JAK2-STAT1/STAT3 signaling. These results also showed that klotho might be used as a unique molecular target for the treatment of diabetic nephropathy.
Subject(s)
Coumarins/pharmacology , Glucuronidase/metabolism , Glycation End Products, Advanced/metabolism , Hypertrophy/drug therapy , Kidney Tubules/drug effects , Antigens, Neoplasm/metabolism , Cell Cycle/drug effects , Cell Line , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/pathology , Glucuronidase/pharmacology , Glycation End Products, Advanced/toxicity , Humans , Hypertrophy/chemically induced , Hypertrophy/pathology , Janus Kinase 2/metabolism , Kidney Tubules/metabolism , Kidney Tubules/pathology , Klotho Proteins , Mitogen-Activated Protein Kinases/metabolism , STAT3 Transcription Factor/metabolism , Suppressor of Cytokine Signaling Proteins/metabolismABSTRACT
Hypothalamic leptin receptor (LR) signaling regulates body weight by balancing food intake and energy expenditure. It is well established that the human LR undergoes ectodomain shedding, but little is known about the fate of the remaining cytosolic domain. This study demonstrates that regulated intramembrane proteolysis (RIP) releases the LR intracellular domain (LR ICD), which translocates to the mitochondria where it binds to SOCS6. This LR ICD-SOCS6 interaction stabilizes both proteins on the mitochondrial outer membrane and requires a functional BC box in SOCS6 for mitochondrial association and a central motif in the LR ICD for SOCS6 binding. The LR ICD prevents CCCP-induced mitochondrial depolarization and mitophagy as shown by lowered Parkin translocation and p62 accumulation. Strict regulation of mitochondrial dynamics in the hypothalamus is known to be essential for body weight homeostasis. This is the first study showing that the LR can directly modulate mitochondrial biology.
Subject(s)
Mitochondria/physiology , Receptors, Leptin/chemistry , Receptors, Leptin/metabolism , Suppressor of Cytokine Signaling Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism , Carbonyl Cyanide m-Chlorophenyl Hydrazone/pharmacology , Cell Line, Tumor , Cell Polarity/drug effects , HEK293 Cells , HeLa Cells , Humans , Hypothalamus/metabolism , Mitochondria/drug effects , Mitophagy , Protein Domains , ProteolysisABSTRACT
Paeoniflorin is a natural monoterpene glycoside in Paeonia lactiflora pall with various biological properties including promising anti-inflammatory activity. Current evidences support that inflammatory reaction, oxidative stress, as well as abnormal insulin signaling in the hippocampus are potential causes of tau hyperphosphorylation and finally induce cognitive dysfunction. The present study aims to explore the effects of paeoniflorin on the cognitive deficits and investigate the underlying mechanisms in diabetic rats induced by a high-sucrose, high-fat diet and low dose of streptozotocin (STZ). Paeoniflorin treatment effectively improved the performance of diabetic rats in the Morris water maze test via decreasing escape latency and increasing the spent time in the target quadrant. Immunohistochemistry staining also had shown that tau hyperphosphorylation in the hippocampus was prevented after paeoniflorin administration. This function was correlated with its abilities of reducing the brain inflammatory cytokines (IL-1ß and TNF-α), decreasing suppressor of cytokine signaling 2 (SOCS2) expressions and promoting insulin receptor substrate-1 (IRS-1) activity. Additionally, we also found paeoniflorin administration significantly promoted the phosphorylation levels of protein kinase B (Akt) and glycogen synthase kinase-3ß (GSK-3ß). Together, these results showed that paeoniflorin had beneficial effects on relieving diabetes-associated cognitive deficits via regulating SOCS2/IRS-1 pathway and might provide a feasible method for the treatment of diabetes-associated cognitive dysfunction.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Cognition Disorders/drug therapy , Cognition Disorders/etiology , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/drug therapy , Glucosides/therapeutic use , Monoterpenes/therapeutic use , Signal Transduction/drug effects , Animals , Blood Glucose/drug effects , Cytokines/metabolism , Diabetes Mellitus, Experimental/chemically induced , Disease Models, Animal , Dose-Response Relationship, Drug , Hippocampus/drug effects , Hippocampus/metabolism , Insulin Receptor Substrate Proteins/metabolism , Male , Maze Learning/drug effects , Phosphorylation/drug effects , Random Allocation , Rats , Rats, Sprague-Dawley , Suppressor of Cytokine Signaling Proteins/metabolism , tau Proteins/metabolismABSTRACT
Streptococcus pneumoniae is a major human pathogen and a leading cause of pneumonia, septicemia, and meningitis worldwide. Despite clinical studies linking vitamin D deficiency and pneumonia, molecular mechanisms behind these observations remain unclear. In particular, the effects of vitamin D on neutrophil responses remain unknown. Using pneumococcal strains, primary neutrophils isolated from human blood, and sera from patients with frequent respiratory tract infections (RTIs), we investigated the effects of vitamin D on neutrophil bactericidal and inflammatory responses, including pattern recognition receptors, antimicrobial peptides, and cytokine regulation. We found that vitamin D upregulated pattern recognition receptors, TLR2, and NOD2, and induced the antimicrobial human neutrophil peptides (HNP1-3) and LL-37, resulting in increased killing of pneumococci in a vitamin D receptor-dependent manner. Antibodies targeting HNP1-3 inhibited bacterial killing. Vitamin D supplementation of serum from patients with bacterial RTIs enhanced neutrophil killing. Moreover, vitamin D lowered inflammatory cytokine production by infected neutrophils via IL-4 production and the induction of suppressor of cytokine signaling (SOCS) proteins SOCS-1 and SOCS-3, leading to the suppression of NF-κB signaling. Thus, vitamin D enhances neutrophil killing of S. pneumoniae while dampening excessive inflammatory responses and apoptosis, suggesting that vitamin D could be used alongside antibiotics when treating pneumococcal infections.
Subject(s)
Inflammation/drug therapy , Neutrophils/immunology , Pneumococcal Infections/drug therapy , Streptococcus pneumoniae/immunology , Vitamin D/pharmacology , Bacteriolysis , Cells, Cultured , Humans , Immunomodulation , Interleukin-4/metabolism , NF-kappa B/metabolism , Nod2 Signaling Adaptor Protein/genetics , Nod2 Signaling Adaptor Protein/metabolism , Primary Cell Culture , Signal Transduction , Suppressor of Cytokine Signaling 1 Protein/genetics , Suppressor of Cytokine Signaling 1 Protein/metabolism , Suppressor of Cytokine Signaling Proteins/genetics , Suppressor of Cytokine Signaling Proteins/metabolism , Toll-Like Receptor 2/genetics , Toll-Like Receptor 2/metabolism , alpha-Defensins/genetics , alpha-Defensins/metabolismABSTRACT
BACKGROUND: Signal transducer and activator of transcription 3 (STAT3) is persistently activated in squamous cell carcinoma of the head and neck (SCCHN) and can cause uncontrolled cellular proliferation and division. HYPOTHESIS: Thus, its targeted abrogation could be an effective strategy to reduce the risk of SCCHN. Resveratrol is known for its anti-cancer efficacy in a variety of cancer models. STUDY DESIGN: The effect resveratrol on STAT3 activation, associated protein kinases, phosphatases, cellular proliferation and apoptosis was investigated. METHODS: We evaluated the effect of resveratrol on STAT3 signaling cascade and its regulated functional responses in SCCHN cells. RESULTS: We found that HN3 and FaDu cells expressed strongly phosphorylated STAT3 on both tyrosine 705 and serine 727 residues as compared to other SCCHN cells. The phosphorylation was completely suppressed by resveratrol in FaDu cells, but not substantially in HN3 cells. STAT3 suppression was mediated through the inhibition of activation of upstream JAK2, but not of JAK1 and Src kinases. Treatment with the protein tyrosine phosphatase (PTP) inhibitor pervanadate reversed the resveratrol-induced down-regulation of STAT3, thereby indicating a critical role for a PTP. We also found that resveratrol induced the expression of the SOCS-1 protein and mRNA. Further, deletion of SOCS-1 gene by siRNA suppressed the induction of SOCS-1, and reversed the inhibition of STAT3 activation. Resveratrol down-regulated various STAT3-regulated gene products, inhibited proliferation, invasion, as well as induced the cell accumulation in the sub-G1 phase and caused apoptosis. Beside, this phytoalexin also exhibited the enhancement of apoptosis when combined with ionizing radiation treatment. CONCLUSION: Our results suggest that resveratrol blocks STAT3 signaling pathway through induction of SOCS-1, thus attenuating STAT3 phosphorylation and proliferation in SCCHN cells.
Subject(s)
Carcinoma, Squamous Cell/pathology , Head and Neck Neoplasms/pathology , Radiation-Sensitizing Agents/pharmacology , STAT3 Transcription Factor/antagonists & inhibitors , Signal Transduction/drug effects , Stilbenes/pharmacology , Suppressor of Cytokine Signaling Proteins/metabolism , Apoptosis/drug effects , Cell Line, Tumor/drug effects , Cell Line, Tumor/radiation effects , Cell Proliferation/drug effects , Down-Regulation , Humans , Janus Kinase 1/metabolism , Janus Kinase 2/metabolism , Phosphorylation/drug effects , Resveratrol , STAT3 Transcription Factor/metabolism , Squamous Cell Carcinoma of Head and Neck , Suppressor of Cytokine Signaling 1 Protein , src-Family Kinases/metabolismABSTRACT
Leptin is a permissive factor for the onset of puberty. However, changes in adiposity frequently influence leptin sensitivity. Thus, the objective of the present study was to investigate how changes in body weight, fatness, leptin levels and leptin sensitivity interact to control the timing of puberty in female mice. Pre-pubertal obesity, induced by raising C57BL/6 mice in small litters, led to an early puberty onset. Inactivation of Socs3 gene in the brain or exclusively in leptin receptor-expressing cells reduced the body weight and leptin levels at pubertal onset, and increased leptin sensitivity. Notably, these female mice exhibited significant delays in vaginal opening, first estrus and onset of estrus cyclicity. In conclusion, our findings suggest that increased leptin sensitivity did not play an important role in favoring pubertal onset in female mice. Rather, changes in pubertal body weight, fatness and/or leptin levels were more important in influencing the timing of puberty.
Subject(s)
Leptin/physiology , Obesity/physiopathology , Sexual Maturation , Animals , Body Weight , Estrous Cycle/physiology , Female , Gene Knockout Techniques , Hypothalamus/metabolism , Mice, 129 Strain , Mice, Inbred C57BL , Mice, Knockout , Nestin/genetics , Nestin/metabolism , Receptors, Leptin/metabolism , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/genetics , Suppressor of Cytokine Signaling Proteins/metabolismABSTRACT
We aimed to evaluate the effects of maternal and/or paternal obesity on offspring body mass, leptin signaling, appetite-regulating neurotransmitters and local inflammatory markers. C57BL/6 mice received standard chow (SC, lean groups) or high-fat diet (HF, obese groups) starting from one month of age. At three months, HF mice became obese relative to SC mice. They were then mated as follows: lean mother and lean father, lean mother and obese father, obese mother and lean father, and obese mother and obese father. The offspring received the SC diet from weaning until three months of age, when they were sacrificed. In the offspring, paternal obesity did not lead to changes in the Janus kinase (JAK)/signal transducer and activation of the transcription (STAT) pathway or feeding behavior but did induce hypothalamic inflammation. On the other hand, maternal obesity resulted in increased weight gain, hyperleptinemia, decreased leptin OBRb receptor expression, JAK/STAT pathway impairment, and increased SOCS3 signaling in the offspring. In addition, maternal obesity elevated inflammatory markers and altered NPY and POMC expression in the hypothalamus. Interestingly, combined parental obesity exacerbated the deleterious outcomes compared to single-parent obesity. In conclusion, while maternal obesity is known to program metabolic changes and obesity in offspring, the current study demonstrated that obese fathers induce hypothalamus inflammation in offspring, which may contribute to the development of metabolic syndromes in adulthood.
Subject(s)
Hyperphagia/metabolism , Hypothalamus/metabolism , Inflammation Mediators/metabolism , Leptin/metabolism , Obesity/metabolism , Parents , Signal Transduction , Animals , Body Weight , Diet, High-Fat , Energy Intake , Fathers , Female , Janus Kinase 1/metabolism , Leptin/blood , Male , Mice , Mothers , Neuropeptide Y/biosynthesis , Obesity/chemically induced , Obesity/physiopathology , Pro-Opiomelanocortin/biosynthesis , Receptors, Leptin/biosynthesis , STAT1 Transcription Factor/metabolism , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/metabolismABSTRACT
Natural compounds derived from medicinal plants have long been considered a rich source of novel therapeutic agents. Baicalin (Ba) is a bioactive flavonoid compound derived from the root of Scutellaria baicalensis, an herb widely used in traditional medicine for the treatment of various inflammatory diseases. In this study, we investigate the effects and mechanism of action of Ba in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Ba treatment effectively ameliorated clinical disease severity in myelin oligodendrocyte glycoprotein (MOG)35-55 peptide-induced EAE, and reduced inflammation and demyelination of the central nervous system (CNS). Ba reduced infiltration of immune cells into the CNS, inhibited expression of proinflammatory molecules and chemokines, and prevented Th1 and Th17 cell differentiation via STAT/NFκB signaling pathways. Further, we showed that SOCS3 induction is essential to the effects of Ba, given that the inhibitory effect of Ba on pathogenic Th17 responses was largely abolished when SOCS3 signaling was knocked down. Taken together, our findings demonstrate that Ba has significant potential as a novel anti-inflammatory agent for therapy of autoimmune diseases such as MS.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Encephalomyelitis, Autoimmune, Experimental/immunology , Encephalomyelitis, Autoimmune, Experimental/metabolism , Flavonoids/pharmacology , Signal Transduction/drug effects , Suppressor of Cytokine Signaling Proteins/metabolism , Animals , Cell Differentiation/drug effects , Cell Differentiation/genetics , Cytokines/metabolism , Disease Models, Animal , Encephalomyelitis, Autoimmune, Experimental/drug therapy , Encephalomyelitis, Autoimmune, Experimental/pathology , Female , Inflammation Mediators/metabolism , Lymphocyte Activation/drug effects , Lymphocyte Activation/genetics , Lymphocyte Activation/immunology , Mice , Multiple Sclerosis/drug therapy , Multiple Sclerosis/immunology , Multiple Sclerosis/metabolism , Multiple Sclerosis/pathology , NF-kappa B/metabolism , STAT Transcription Factors/metabolism , Suppressor of Cytokine Signaling 3 Protein , T-Lymphocyte Subsets/cytology , T-Lymphocyte Subsets/drug effects , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Th1 Cells/cytology , Th1 Cells/drug effects , Th1 Cells/immunology , Th1 Cells/metabolism , Th17 Cells/cytology , Th17 Cells/drug effects , Th17 Cells/immunology , Th17 Cells/metabolismABSTRACT
In traditional Chinese medicine (TCM), Dangguiliuhuang decoction (DGLHD) is an effective treatment of autoimmune diabetes. Here, we studied potential anti-diabetic mechanisms of DGLHD in a non-obese diabetic (NOD) mouse model. In vitro, DGLHD and individual active ingredients enhanced glucose uptake in HepG2 cells, inhibited T lymphocyte proliferation, and suppressed dendritic cells (DCs) function. In vivo, DGLHD significantly inhibited insulitis, delayed the onset and development of diabetes, promoted insulin secretion and sensitivity, and balanced partially normalized Th1 and Th2 cytokines in NOD mice. In addition, DGLHD increased α1-antitrypsin (AAT-1), Bcl-2, and CyclinD1, and decreased Bax levels in pancreas, spleen, thymus, DCs, and a NIT-1 cell line, all consistent with protecting and repairing islet ß cell. More detailed studies indicated that DGLHD regulated the maturation and function of DCs, decreased the percentage of merocytic dendritic cells (mcDCs) subset, and increased programmed death ligand-1 (PD-L1) expression in DCs. DGLHD also impeded T lymphocyte proliferation and promoted regulatory T cells (T(regs)) differentiation in vivo. A JAK2-STAT3-dependent pathway was involved in the suppression by DGLHD of interactions between DCs and T lymphocyte. The experiments implicated five active ingredients in specific anti-diabetic actions of DGLHD. The results demonstrated the reasonable composition of the formula.
Subject(s)
Cell Communication/immunology , Dendritic Cells/immunology , Diabetes Mellitus, Type 1/immunology , Drugs, Chinese Herbal/pharmacology , T-Lymphocytes/immunology , Animals , Antigens/immunology , Cell Differentiation/drug effects , Cell Differentiation/immunology , Cell Movement/drug effects , Cell Movement/immunology , Cytokines/metabolism , Dendritic Cells/metabolism , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/metabolism , Disease Models, Animal , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/immunology , Insulin-Secreting Cells/metabolism , Islets of Langerhans/drug effects , Islets of Langerhans/metabolism , Islets of Langerhans/pathology , Janus Kinase 2/metabolism , Lymphocyte Activation/drug effects , Lymphocyte Activation/immunology , Medicine, Chinese Traditional , Mice , Mice, Inbred NOD , STAT3 Transcription Factor/metabolism , Signal Transduction/drug effects , Spleen/immunology , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/metabolism , T-Lymphocytes/cytology , T-Lymphocytes/metabolism , T-Lymphocytes, Regulatory/cytology , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/metabolism , Th2 Cells/immunology , Th2 Cells/metabolism , Toll-Like Receptor 4/metabolismABSTRACT
Mice lacking the RIIß regulatory subunit of cyclic AMP-dependent protein kinase A (PKA) display reduced adiposity and resistance to diet-induced obesity. Here we show that RIIß knockout (KO) mice have enhanced sensitivity to leptin's effects on both feeding and energy metabolism. After administration of a low dose of leptin, the duration of hypothalamic JAK/STAT3 signalling is increased, resulting in enhanced POMC mRNA induction. Consistent with the extended JAK/STAT3 activation, we find that the negative feedback regulator of leptin receptor signalling, Socs3, is inhibited in the hypothalamus of RIIß KO mice. During fasting, RIIß-PKA is activated and this correlates with an increase in CREB phosphorylation. The increase in CREB phosphorylation is absent in the fasted RIIß KO hypothalamus. Selective inhibition of PKA activity in AgRP neurons partially recapitulates the leanness and resistance to diet-induced obesity of RIIß KO mice. Our findings suggest that RIIß-PKA modulates the duration of leptin receptor signalling and therefore the magnitude of the catabolic response to leptin.
Subject(s)
Adiposity/genetics , Cyclic AMP-Dependent Protein Kinase RIIbeta Subunit/genetics , Hypothalamus/metabolism , Leptin/metabolism , Neurons/metabolism , RNA, Messenger/metabolism , Receptors, Leptin/metabolism , Agouti-Related Protein/metabolism , Animals , Cyclic AMP Response Element-Binding Protein/metabolism , Cyclic AMP-Dependent Protein Kinase RIIbeta Subunit/metabolism , Cyclic AMP-Dependent Protein Kinases/genetics , Cyclic AMP-Dependent Protein Kinases/metabolism , Diet, High-Fat , Feedback, Physiological , Janus Kinases/metabolism , Leptin/pharmacology , Mice , Mice, Knockout , Neuropeptide Y/metabolism , Obesity/genetics , Phosphorylation , Pro-Opiomelanocortin/genetics , Pro-Opiomelanocortin/metabolism , STAT3 Transcription Factor/metabolism , Signal Transduction , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/metabolismABSTRACT
OBJECTIVES: To investigate the therapeutic effects of OM-85 BV as an adjunctive treatment on experimental chronic rhinosinusitis (CRS) in mice. METHODOLOGY: Female BALB/c mice aged 8-12 weeks were sensitized and administrated by intranasal Aspergillus fumigatis (AF) three times per week for 1 week, 3 weeks, 2 months and 3 months (n = 10 each time point). The mice were randomly and equally assigned to four groups: normal control group, model group, OM-85-BV plus amoxicillin group, and isolated amoxicillin group. Inflammatory changes were determined by hematoxylin-eosin (HE) staining. The expression levels of suppressor of cytokine signaling (SOCS) 1, SOCS3, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ in samples were assessed by using real-time PCR (RT-PCR) and Western blotting. RESULTS: There were significantly inflammatory and structural changes between the model and other groups. Compared to the model group, the mRNA expression levels of SOCS1, SOCS3, TNF-α, and IFN-γ were significantly decreased in OM-85-BV plus amoxicillin group and isolated amoxicillin group, along with the protein levels. CONCLUSION: The bacterial extract OM-85 BV is a low-cost alternatively adjunctive drug to treat CRS with simple oral administration, good safety, and few side effects.