Corticotropin-releasing factor receptor signaling and modulation: implications for stress response and resilience

Abstract Introduction In addition to their role in regulation of the hypothalamic-pituitary-adrenal-axis, corticotropin-releasing factor (CRF) and its related peptides, the urocortins, are important mediators of physiological and pathophysiological processes of the central nervous, cardiovascular, gastrointestinal, immune, endocrine, reproductive, and skin systems. Altered regulation of CRF-mediated adaptive responses to various stressful stimuli disrupts healthy function and might confer vulnerability to several disorders, including depression and anxiety. Methodology This narrative review was conducted through search and analysis of studies retrieved from online databases using a snowball method. Results This review covers aspects beginning with the discovery of CRF, CRF binding protein and their actions via interaction with CRF receptors type 1 and type 2. These are surface plasma membrane receptors, activation of which is associated with conformational changes and interaction with a variety of G-proteins and signaling pathways. We also reviewed the pharmacology and mechanisms of the receptor signaling modulatory activity of these receptors. Conclusion This review compiles and presents knowledge regarding the CRFergic system, including CRF related peptides, CRF binding protein, and CRF receptors, as well as some evidence that is potentially indicative of the biological roles of these entities in several physiological and pathophysiological processes.

Smad1/5 signal transduction regulates the ameloblastic differentiation of induced pluripotent stem cells

Abstract Induced pluripotent stem (iPS) cells could be induced into ameloblast-like cells by ameloblasts serum-free conditioned medium (ASF-CM), and bone morphogenetic proteins (BMPs) might be essential during the regulation of this process. The present study investigates the signal transduction that regulates the ameloblastic differentiation of iPS cells induced by ASF-CM. Mouse iPS cells were characterized and then cultured for 14 days in epithelial cell medium (control) or ASF-CM. Bone morphogenetic protein receptor II (BMPR-II) siRNA, inhibitor of Smad1/5 phosphorylation activated by activin receptor-like kinase (ALK) receptors, and inhibitors of mitogen-activated protein kinases (MAPKs) phosphorylation were used to treat the iPS cells in combination with ASF-CM. Real-time PCR, western blotting, and immunofluorescent staining were used to evaluate the expressions of ameloblast markers ameloblastin, enamelin, and cytokeratin-14. BMPR-II gene and protein levels increased markedly in ASF-CM-treated iPS cells compared with the controls, while the mRNA levels of Bmpr-Ia and Bmpr-Ib were similar between the ASF-CM and control groups. ASF-CM stimulation significantly increased the gene and protein expression of ameloblastin, enamelin and cytokeratin-14, and phosphorylated SMAD1/5, p38 MAPK, and ERK1/2 MAPK compared with the controls. Knockdown of BMPR-II and inhibition of Smad1/5 phosphorylation both could significantly reverse the increased expression of ameloblastin, enamelin, and cytokeratin-14 induced by ASF-CM, while neither inhibition of p38 nor ERK1/2 phosphorylation had significant reversing effects. We conclude that smad1/5 signaling transduction, activated by ALK receptors, regulates the ameloblastic differentiation of iPS cells induced by ameloblast-conditioned medium.

Smad1/5 signal transduction regulates the ameloblastic differentiation of induced pluripotent stem cells

Abstract Induced pluripotent stem (iPS) cells could be induced into ameloblast-like cells by ameloblasts serum-free conditioned medium (ASF-CM), and bone morphogenetic proteins (BMPs) might be essential during the regulation of this process. The present study investigates the signal transduction that regulates the ameloblastic differentiation of iPS cells induced by ASF-CM. Mouse iPS cells were characterized and then cultured for 14 days in epithelial cell medium (control) or ASF-CM. Bone morphogenetic protein receptor II (BMPR-II) siRNA, inhibitor of Smad1/5 phosphorylation activated by activin receptor-like kinase (ALK) receptors, and inhibitors of mitogen-activated protein kinases (MAPKs) phosphorylation were used to treat the iPS cells in combination with ASF-CM. Real-time PCR, western blotting, and immunofluorescent staining were used to evaluate the expressions of ameloblast markers ameloblastin, enamelin, and cytokeratin-14. BMPR-II gene and protein levels increased markedly in ASF-CM-treated iPS cells compared with the controls, while the mRNA levels of Bmpr-Ia and Bmpr-Ib were similar between the ASF-CM and control groups. ASF-CM stimulation significantly increased the gene and protein expression of ameloblastin, enamelin and cytokeratin-14, and phosphorylated SMAD1/5, p38 MAPK, and ERK1/2 MAPK compared with the controls. Knockdown of BMPR-II and inhibition of Smad1/5 phosphorylation both could significantly reverse the increased expression of ameloblastin, enamelin, and cytokeratin-14 induced by ASF-CM, while neither inhibition of p38 nor ERK1/2 phosphorylation had significant reversing effects. We conclude that smad1/5 signaling transduction, activated by ALK receptors, regulates the ameloblastic differentiation of iPS cells induced by ameloblast-conditioned medium.

Insulin signaling in the whole spectrum of GH deficiency

ABSTRACT GH is one of the insulin counterregulatory hormones which acts in the opposite way to insulin, increasing the glucose production by the liver and kidneys and decreasing glucose uptake from peripheral tissues, thus being a hyperglycemic hormone. When in excess, as in acromegaly, it induces glucose intolerance and diabetes. As expected, patients with GH deficiency (GHD) have hypoglycemia, especially in early childhood, but as GH is also a lipolytic hormone, these patients are becoming obese with higher percentages of body fat. Although obesity in general is directly related to insulin resistance, in patients with GH secretion disorders this relationship may be altered. In acromegaly there is a decrease in fat mass with worsening insulin sensitivity and mice with isolated GHD are characterized by greater insulin sensitivity despite excess fat mass. In humans with GHD, body composition shows increased body fat and decreased free fat mass, but the results regarding insulin sensitivity are still controversial in these patients. These discrepant results regarding insulin sensitivity in patients with GHD suggest the existence of other variables influencing these results. In the present review, we will try to follow the path of the different researches conducted on this subject, both in animal and human models, with the goal of understanding the current knowledge of insulin sensitivity across the spectrum of GHD. Arch Endocrinol Metab. 2019;63(6):582-91

Non-alcoholic fatty pancreatic disease and insulin resistance: overlooked complication of obstructive sleep apnea and hypopnea syndrome - signaling pathway diagram / Doença pancreática gordurosa não alcoólica e resistência insulínica: complicação negligenciada da síndrome de apneia e hipopneia obstrutiva do sono

Objective: To demonstrate the interaction between obstructive sleep apnea/hypopnea syndrome, insulin resistance, and non-alcoholic fatty pancreatic disease through the signaling pathway diagram. Methods: To investigate the involvement of metabolic signaling pathway, a search was performed using the Kyoto Encyclopedia of Genes and Genomes. The signaling pathway mapping was performed using the automatic annotation server of this encyclopedia. The Modeller 9.19 package was used to predict 3-dimensional structures based on the homology modeling protocol. The signaling pathway map was performed using PathVisio software, which is a free available signaling pathway drawing software. Based on the 3-dimensional structures, we have designed several peptide activators of the signaling pathway of non-alcoholic fatty pancreatic disease. Results: The contigs were taken from the Kyoto Encyclopedia of Genes and Genomes database and their mapped transcription represented the signaling pathway of the main biomolecules that triggered non-alcoholic fatty pancreatic disease. The interaction between obstructive sleep apnea/hypopnea syndrome, insulin resistance, and inflammatory factors contributes to the possible development of fatty infiltration of pancreas, leading to the loss of function of the pancreatic ß-cells, and even to the development of other metabolic diseases. Conclusion: The interaction between obstructive sleep apnea/hypopnea syndrome and insulin resistance demonstrated through the signaling pathway contributes to the possible development of non-alcoholic fatty pancreatic disease. (AU)

Objetivo: Demonstrar a interação entre a síndrome de apneia/ hipopneia obstrutiva do sono, a resistência à insulina e a doença pancreática gordurosa não alcoólica considerando o desenho de uma via de sinalização. Métodos: Para avaliar o envolvimento da via de sinalização metabólica, realizou-se uma pesquisa usando a Enciclopédia de Genes e Genomas de Kyoto. O mapeamento da via de sinalização foi realizado com o servidor de anotação automático desta enciclopédia. O software MODELLER 9.19 foi usado para prever estruturas tridimensionais, com base no protocolo de modelagem por homologia. O desenho da via de sinalização foi realizado por meio do programa PathVisio, um software de domínio público para desenho de via de sinalização. Com base nas estruturas tridimensionais, desenhamos os vários ativadores peptídicos da via de sinalização da esteatose pancreática. Resultados: Os contigs foram retirados do banco de dados da Enciclopédia de Genes e Genomas de Kyoto, e sua transcrição mapeada representou a via de sinalização das principais biomoléculas que desencadearam doença pancreática gordurosa não alcoólica. A interação entre síndrome de apneia/hipopneia obstrutiva do sono, resistência à insulina e fatores inflamatórios contribuiu para o possível desenvolvimento de infiltração gordurosa do pâncreas, levando à perda de função das células beta pancreáticas e até mesmo ao desenvolvimento de outras doenças metabólicas. Conclusão: A interação entre síndrome de apneia/hipopneia obstrutiva do sono e resistência à insulina demonstrada pela via de sinalização contribui para o possível desenvolvimento de doença pancreática gordurosa não alcoólica. (AU)

The role of PI3K/Akt signal pathway in the protective effects of propofol on intestinal and lung injury induced by intestinal ischemia/reperfusion

Abstract Purpose: To investigate the role of PI3k/Akt signal pathway in the protective effects of propofol on intestinal and lung injury induced by intestinal ischemia/reperfusion(I/R). Methods: Male Sprague-Dawley rats were subjected to 45 min of ischemia by occluding the superior mesenteric artery and to 2h of reperfusion to establish the model of I/R. Twenty four rats were randomly divided into four groups: Sham, intestinal I/R (II/R), propofol (P), wortmannin (W). In groups P, W, propofol was injected intravenously and continuously at the onset of reperfusion via infusion pump. PI3K inhibitor (wortmannin) was administered intravenously in group W 25 min before ischemia. Intestinal tissues and lung tissues were obtained for determination of histologic injury, wet/dry weight ratio, malondialdehyde (MDA) levels, superoxide dismutase (SOD) and myeloperoxidase (MPO) activities. Meanwhile, the expressions of caspase-3 and phosphorylated Akt (p-Akt) in intestines and lungs were detected by western blot. Results: Propofol treatment alleviated intestinal and lung morphological changes which were observed in II/R group，Moreover, wet/dry weight ratio, the MDA level, MPO activity and expression of caspase-3 were significantly decreased whereas the SOD activity and p-Akt expression were significantly increased. Notably, the protections were significantly reversed by pretreatment of wortmannin. Conclusion: PI3K/Akt pathway activation play a critical role in the protective effects of propofol on intestinal and lung injury induced by ischemia/reperfusion.

Oxiracetam ameliorates cognitive deficits in vascular dementia rats by regulating the expression of neuronal apoptosis/autophagy-related genes associated with the activation of the Akt/mTOR signaling pathway

Oxiracetam (ORC) is a commonly used nootropic drug for improving cognition and memory impairments. The therapeutic effect and underlying mechanism of ORC in vascular dementia (VaD) treatment remain unknown. In this study, 3-month-old male Sprague-Dawley rats with permanent bilateral common carotid artery occlusion-induced VaD were treated orally with low (100 mg/kg) or high (200 mg/kg) dose ORC once a day for 4 weeks. The results of the Morris water maze test and Nissl staining showed that ORC treatment significantly alleviated learning and memory deficits and neuronal damage in rats with VaD. Mechanistically, the protein levels of a panel of genes associated with neuronal apoptosis (Bcl-2, Bax) and autophagy (microtubule-associated protein 1 chain 3, Beclin1, p62) were significantly altered by ORC treatment compared with VaD, suggesting a protective role of ORC against VaD-induced neuronal apoptosis and autophagy. Moreover, the Akt/mTOR pathway, which is known to be the upstream signaling governing apoptosis and autophagy, was found to be activated in ORC-treated rats, suggesting an involvement of Akt/mTOR activation in ORC-rendered protection in VaD rats. Taken together, this study demonstrated that ORC may alleviate learning and memory impairments and neuronal damage in VaD rats by altering the expression of apoptosis/autophagy-related genes and activation of the Akt/mTOR signaling pathway in neurons.

Ca2+/Calmodulin-dependent kinase II delta B is essential for cardiomyocyte hypertrophy and complement gene expression after LPS and HSP60 stimulation in vitro

Inflammation plays an important role in the development of cardiovascular diseases (CVDs), suggesting that the immune system is a target of therapeutic interventions used for treating CVDs. This study evaluated mechanisms underlying inflammatory response and cardiomyocyte hypertrophy associated with bacterial lipopolysaccharide (LPS)- or heat shock protein 60 (HSP60)-induced Toll-like receptor (TLR) stimulation and the effect of a small interfering RNA (siRNA) against Ca2+/calmodulin-dependent kinase II delta B (CaMKIIδB) on these outcomes. Our results showed that treatment with HSP60 or LPS (TLR agonists) induced cardiomyocyte hypertrophy and complement system C3 and factor B gene expression. In vitro silencing of CaMKIIδB prevented complement gene transcription and cardiomyocyte hypertrophy associated with TLR 2/4 activation but did not prevent the increase in interleukin-6 and tumor necrosis factor-alfa gene expression in primary cultured cardiomyocytes. Moreover, CaMKIIδB silencing attenuated nuclear factor-kappa B expression. These findings supported the hypothesis that CaMKIIδB acts as a link between inflammation and cardiac hypertrophy. Furthermore, the present study is the first to show that extracellular HSP60 activated complement gene expression through CaMKIIδB. Our results indicated that a stress stimulus induced by LPS or HSP60 treatment promoted cardiomyocyte hypertrophy and initiated an inflammatory response through the complement system. However, CaMKIIδB silencing prevented the cardiomyocyte hypertrophy independent of inflammatory response induced by LPS or HSP60 treatment.

Role of JNK and ERK1/2 MAPK signaling pathway in testicular injury of rats induced by di-N-butyl-phthalate (DBP)

BACKGROUND: Di-N-butyl-phthalate (DBP) is an endocrine disrupting substance. We investigated the adverse effect of DBP on testis of male rat and reveal its potential mechanism of MAPK signaling pathway involved this effect in vivo and in vitro. Gonadal hormone, sperm quality, morphological change and the activation status of JNK, ERK1/2 and p38 was determined in vivo. Primary Sertoli cell was established and cultivated with JNK, ERK1/2 inhibitors, then determine the cell viability, apoptosis and the expression of p-JNK, p-ERK1/2. Data in this study were presented as mean ± SD and determined by one-way analysis of variance (ANOVA) followed by Bonferroni's test. Difference was considered statistically significant at P < 0.05. RESULTS: In vivo experiment, DBP impaired the normal structure of testicular tissue, reduced testosterone levels in blood serum, decreased sperm count and increased sperm abnormality, p-ERK1/2 and p-JNK in rat testicular tissue increased in a dose-dependent manner. In vitro studies, DBP could decrease the viability of Sertoli cells and increase p-ERK1/2 and p-JNK. Cell apoptosis in SP600125 + DBP group was significantly lower than in DBP group (P < 0.05). p-JNK was not significantly decreased in SP600125 + DBP group, while p-ERK1/2 was significantly decreased in U0126 + DBP group. CONCLUSIONS: These results suggest that DBP can lead to testicular damage and the activation of ERK1/2 and JNK pathways, the JNK signaling pathway may be primarily associated with its effect.

Derlin1 functions as an oncogene in cervical cancer via AKT/mTOR signaling pathway

BACKGROUND: Cervical cancer (CC) ranks third in the morbidity and mortality of female cancer around the world. Derlin1 has been found to be overexpressed in several human cancers. However, it is still unclear about its roles in CC. The research aims to explore the relationship between Derlin1 and CC. METHODS: We purchased a human CC tissues microarray, which contained CC tissues and corresponding para-cancerous tissues from 93 patients with primary cervical squamous cell carcinoma. Immunohistochemical staining was used to confirm the expression of Derlin1 in these tissues. And we detected the differential expression of Derlin1 in cervical cancer cell lines and normal cervical epithelial cells (H8). Further, the cervical cancer cell lines SiHa and C33A were used as an in vitro model, which was down-regulated the expression of Derlin1 using siRNA interference technology. The effects of Derlin1 down-regulating in CC cell lines on cell proliferation and migration were detected by CCK8 assay and transwell assay, respectively. The effect of Derlin1 down-regulating on apoptosis was analyzed by flow cytometry, and apoptosis-related proteins were detected using western blotting. In-depth mechanisms were studied using western blotting. In addition, the effects of Derlin1 up-regulating in normal cervical epithelial cells also were exposed. RESULTS: Derlin1 was significantly elevated in CC tissues (81.7%, 76/93), and the expression of Derlin 1 was positively correlated with the tumor size, pathological grade, and lymph node metastasis in CC patients. And Derlin 1 was high expressed in cervical cancer cell lines compared to H8 cells. Knockdown of Derlin 1 in cervical cancer cell lines inhibited cell proliferation and migration. Moreover, knockdown of Derlin 1 induced apoptosis and affected the expression of apoptosis-related proteins, including Bcl-2, Bax, Bim, caspase3 and caspase9. Further experiments showed that AKT/mTOR signal pathway might be involve in this processes that knockdown of Derlin 1 inhibited the expression of p-AKT and p-mTOR. Over-expression of Derlin 1 in H8 cells promoted cell proliferation and migration via up-regulated the expression of p-AKT and p-mTOR. CONCLUSION: Derlin 1 is an oncogene in CC via AKT/mTOR pathway. It might be a potential therapeutic target for CC.

Insulin Substrate Receptor (IRS) proteins in normal and malignant hematopoiesis

The insulin receptor substrate (IRS) proteins are a family of cytoplasmic proteins that integrate and coordinate the transmission of signals from the extracellular to the intracellular environment via transmembrane receptors, thus regulating cell growth, metabolism, survival and proliferation. The PI3K/AKT/mTOR and MAPK signaling pathways are the best-characterized downstream signaling pathways activated by IRS signaling (canonical pathways). However, novel signaling axes involving IRS proteins (noncanonical pathways) have recently been identified in solid tumor and hematologic neoplasm models. Insulin receptor substrate-1 (IRS1) and insulin receptor substrate-2 (IRS2) are the best-characterized IRS proteins in hematologic-related processes. IRS2 binds to important cellular receptors involved in normal hematopoiesis (EPOR, MPL and IGF1R). Moreover, the identification of IRS1/ABL1 and IRS2/JAK2V617F interactions and their functional consequences has opened a new frontier for investigating the roles of the IRS protein family in malignant hematopoiesis. Insulin receptor substrate-4 (IRS4) is absent in normal hematopoietic tissues but may be expressed under abnormal conditions. Moreover, insulin receptor substrate-5 (DOK4) and insulin receptor substrate-6 (DOK5) are linked to lymphocyte regulation. An improved understanding of the signaling pathways mediated by IRS proteins in hematopoiesis-related processes, along with the increased development of agonists and antagonists of these signaling axes, may generate new therapeutic approaches for hematological diseases. The scope of this review is to recapitulate and review the evidence for the functions of IRS proteins in normal and malignant hematopoiesis.

Adrenergic receptor ß3 is involved in the memory consolidation process in mice

Attention and emotion have a positive impact on memory formation, which is related to the activation of the noradrenergic system in the brain. The hippocampus and amygdala are fundamental structures in memory acquisition, which is modulated by noradrenaline through the noradrenergic receptors. Pharmacological studies suggest that memory acquisition depends on the action of both the β3 (β3-AR) and β2 (β2-AR) receptor subtypes. However, the use of animal models with specific knockout for the β3-AR receptor only (β3-ARKO) allows researchers to more accurately assess its role in memory formation processes. In the present study, we evaluated short- and long-term memory acquisition capacity in β3-ARKO mice and wild-type mice at approximately 60 days of age. The animals were submitted to the open field test, the elevated plus maze, object recognition, and social preference. The results showed that the absence of the β3-AR receptor caused no impairment in locomotion and did not cause anxious behavior, but it caused significant impairment of short- and long-term memory compared to wild-type animals. We also evaluated the expression of genes involved in memory consolidation. The mRNA levels for GLUT3, a glucose transporter expressed in the central nervous system, were significantly reduced in the amygdala, but not in the hippocampus of the β3-ARKO animals. Our results showed that β3-AR was involved in the process of acquisition of declarative memory, and its action may be due to the facilitation of glucose absorption in the amygdala.

The physiological and molecular mechanism of brassinosteroid in response to stress: a review

The negative effects of environmental stresses, such as low temperature, high temperature, salinity, drought, heavy metal stress, and biotic stress significantly decrease crop productivity. Plant hormones are currently being used to induce stress tolerance in a variety of plants. Brassinosteroids (commonly known as BR) are a group of phytohormones that regulate a wide range of biological processes that lead to tolerance of various stresses in plants. BR stimulate BRASSINAZOLE RESISTANCE 1 (BZR1)/BRI1-EMS SUPPRESSOR 1 (BES1), transcription factors that activate thousands of BR-targeted genes. BR regulate antioxidant enzyme activities, chlorophyll contents, photosynthetic capacity, and carbohydrate metabolism to increase plant growth under stress. Mutants with BR defects have shortened root and shoot developments. Exogenous BR application increases the biosynthesis of endogenous hormones such as indole-3-acetic acid, abscisic acid, jasmonic acid, zeatin riboside, brassinosteroids (BR), and isopentenyl adenosine, and gibberellin (GA) and regulates signal transduction pathways to stimulate stress tolerance. This review will describe advancements in knowledge of BR and their roles in response to different stress conditions in plants.

Identification of key genes and pathways involved in response to pain in goat and sheep by transcriptome sequencing

PURPOSE: This aim of this study was to investigate the key genes and pathways involved in the response to pain in goat and sheep by transcriptome sequencing. METHODS: Chronic pain was induced with the injection of the complete Freund's adjuvant (CFA) in sheep and goats. The animals were divided into four groups: CFA-treated sheep, control sheep, CFA-treated goat, and control goat groups (n = 3 in each group). The dorsal root ganglions of these animals were isolated and used for the construction of a cDNA library and transcriptome sequencing. Differentially expressed genes (DEGs) were identified in CFA-induced sheep and goats and gene ontology (GO) enrichment analysis was performed. RESULTS: In total, 1748 and 2441 DEGs were identified in CFA-treated goat and sheep, respectively. The DEGs identified in CFA-treated goats, such as C-C motif chemokine ligand 27 (CCL27), glutamate receptor 2 (GRIA2), and sodium voltage-gated channel alpha subunit 3 (SCN3A), were mainly enriched in GO functions associated with N-methyl-D-aspartate (NMDA) receptor, inflammatory response, and immune response. The DEGs identified in CFA-treated sheep, such as gamma-aminobutyric acid (GABA)-related DEGs (gamma-aminobutyric acid type A receptor gamma 3 subunit [GABRG3], GABRB2, and GABRB1), SCN9A, and transient receptor potential cation channel subfamily V member 1 (TRPV1), were mainly enriched in GO functions related to neuroactive ligand-receptor interaction, NMDA receptor, and defense response. CONCLUSIONS: Our data indicate that NMDA receptor, inflammatory response, and immune response as well as key DEGs such as CCL27, GRIA2, and SCN3A may regulate the process of pain response during chronic pain in goats. Neuroactive ligand-receptor interaction and NMDA receptor as well as GABA-related DEGs, SCN9A, and TRPV1 may modulate the process of response to pain in sheep. These DEGs may serve as drug targets for preventing chronic pain.

Protective roles of autophagy in retinal pigment epithelium under high glucose condition via regulating PINK1/Parkin pathway and BNIP3L

BACKGROUND: Our study aimed to investigate the roles of autophagy against high glucose induced response in retinal pigment epithelium (ARPE-19 cells). METHODS: The morphological changes and reactive oxygen species (ROS) generation in ARPE-19 cells under high glucose treatment were respectively detected using the transmission electron microscopy and flow cytometry. The expression levels of Parkin, PINK1, BNIP3L, LC3-I and LC3-II in ARPE-19 cells received high glucose treatment were measured by western blot after pretreatment of carbonyl cyanide m-chlorophenylhydrazone (CCCP), 3-methyladenine (3-MA), N-acetyl cysteine (NAC) or cyclosporin A (CsA) followed by high glucose treatment. RESULTS: ARPE-19 cells subjected to high glucose stress showed an obvious reduction in the LC3-I expression and significant increase in the number of autophagosomes, in the intracellular ROS level, and in the expression levels of Parkin, PINK1, BNIP3L and LC3-II (p < 0.05). Pretreatment with CCCP significantly reduced the LC3-I expression and increased the expression levels of Parkin, PINK1, BNIP3L and LC3-II (p < 0.05). ARPE-19 cells pretreated with CsA under high glucose stress showed markedly down-regulated expressions of Parkin, PINK1 and BNIP3L compared with the cells treated with high glucose (p < 0.05). Pretreatment of ARPE-19 cells with NAC or 3-MA under high glucose stress resulted in a marked reduction in the expression levels of PINK1, BNIP3L and LC3-II (p < 0.05). Meanwhile, the expression level of Parkin in the ARPE-19 cells pretreated with NAC under high glucose stress was comparable with that in the control cells. CONCLUSION: Autophagy might have protective roles against high glucose induced injury in ARPE19 cells via regulating PINK1/Parkin pathway and BNIP3L.

Effects of bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) release from polylactide-poly (ethylene glycol)-polylactide (PELA) microcapsule-based scaffolds on bone

Multiple growth factors can be administered to mimic the natural process of bone healing in bone tissue engineering. We investigated the effects of sequential release of bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) from polylactide-poly (ethylene glycol)-polylactide (PELA) microcapsule-based scaffolds on bone regeneration. To improve the double emulsion/solvent evaporation technique, VEGF was encapsulated in PELA microcapsules, to which BMP-2 was attached. The scaffold (BMP-2/PELA/VEGF) was then fused to these microcapsules using the dichloromethane vapor method. The bioactivity of the released BMP-2 and VEGF was then quantified in rat mesenchymal stem cells (rMSCs). Immunoblotting analysis showed that BMP-2/PELA/VEG promoted the differentiation of rMSCs into osteoblasts via the MAPK and Wnt pathways. Osteoblast differentiation was assessed through alkaline phosphatase expression. When compared with simple BMP-2 plus VEGF group and pure PELA group, osteoblast differentiation in BMP-2/PELA/VEGF group significantly increased. An MTT assay indicated that BMP-2-loaded PELA scaffolds had no adverse effects on cell activity. BMP-2/PELA/VEG promoted the differentiation of rMSCs into osteoblast via the ERK1/2 and Wnt pathways. Our findings indicate that the sequential release of BMP-2 and VEGF from PELA microcapsule-based scaffolds is a promising approach for the treatment of bone defects.

Reactive oxygen species generation mediated by NADPH oxidase and PI3K/Akt pathways contribute to invasion of Streptococcus agalactiae in human endothelial cells

BACKGROUND Streptococcus agalactiae can causes sepsis, pneumonia, and meningitis in neonates, the elderly, and immunocompromised patients. Although the virulence properties of S. agalactiae have been partially elucidated, the molecular mechanisms related to reactive oxygen species (ROS) generation in infected human endothelial cells need further investigation. OBJECTIVES This study aimed to evaluate the influence of oxidative stress in human umbilical vein endothelial cells (HUVECs) during S. agalactiae infection. METHODS ROS production during S. agalactiae-HUVEC infection was detected using the probe CM-H2DCFDA. Microfilaments labelled with phalloidin-FITC and p47phox-Alexa 546 conjugated were analysed by immunofluorescence. mRNA levels of p47phox (NADPH oxidase subunit) were assessed using Real Time qRT-PCR. The adherence and intracellular viability of S. agalactiae in HUVECs with or without pre-treatment of DPI, apocynin (NADPH oxidase inhibitors), and LY294002 (PI3K inhibitor) were evaluated by penicillin/gentamicin exclusion. Phosphorylation of p47phox and Akt activation by S. agalactiae were evaluated by immunoblotting analysis. FINDINGS Data showed increased ROS production 15 min after HUVEC infection. Real-Time qRT-PCR and western blotting performed in HUVEC infected with S. agalactiae detected alterations in mRNA levels and activation of p47phox. Pre-treatment of endothelial cells with NADPH oxidase (DPI and apocynin) and PI3K/Akt pathway (LY294002) inhibitors reduced ROS production, bacterial intracellular viability, and generation of actin stress fibres in HUVECs infected with S. agalactiae. CONCLUSIONS ROS generation via the NADPH oxidase pathway contributes to invasion of S. agalactiae in human endothelial cells accompanied by cytoskeletal reorganisation through the PI3K/Akt pathway, which provides novel evidence for the involvement of oxidative stress in S. agalactiae pathogenesis.

The Role of Histone Deacetylase Inhibitors in Regulation of Akt/GSK-3ß Signaling Pathway in Mice Following Transient Focal Cerebral Ischemia

Abstract Purpose: To investigate whether the neuroprotective effect of TSA on cerebral ischemia reperfusion injury is mediated by the activation of Akt/GSK-3β signaling pathway. Methods: Mice were randomly divided into four groups (n=15): sham group (S); ischemia reperfusion group (IR); ischemia reperfusion and pretreated with TSA group (IR+T); ischemia reperfusion and pretreated with TSA and LY294002 group (IR+T+L). The model of cerebral ischemia reperfusion was established by 1h of MCAO following 24h of reperfusion. TSA (5mg/kg) was intraperitoneally given for 3 days before MCAO, Akt inhibitor, LY294002 (15 nmol/kg) was injected by tail vein 30 min before the MCAO. Results: TSA significantly increased the expression of p-Akt, p-GSK-3β proteins and the levels of SOD, Bcl-2, reduced the infarct volume and the levels of MDA, ROS, TNF-α, IL-1β, Bax, Caspase-3, TUNEL and attenuated neurological deficit in mice with transient MCAO, LY294002 weakened such effect of TSA dramatically. Conclusions: TSA could significantly decrease the neurological deficit and reduce the cerebral infarct volume, oxidative stress, inflammation, as well as apoptosis during cerebral ischemia reperfusion injury, which was achieved by activation of the Akt/GSK-3β signaling pathway.

The role of under-investigated connexins in musculoskeletal tissue: a brief review with emphasis on bone tissue / El papel de las escasamente investigadas conexinas en el tejido músculo-esquelético: una breve revisión con énfasis en el tejido óseo

Connexins (Cxs) are a family of transmembrane proteins that form gap junctions and hemi-channels, which mediate cell-cell communication between neighboring cells and the respective extracellular milieu in different tissues. Most tissues and cell types throughout the body express one or more Cx proteins, highlighting its importance in regulating cell growth, differentiation, adhesion, migration, cell death and others. Moreover, Cx can propagate intracellular signals through its C-terminus domain, and thus function beyond a mere channel. Cx43 is the most highly expressed and most well studied Cx in bone and musculoskeletal tissues, although Cx40, Cx45, Cx46 and more recently, the Cx37 have been described in bone tissue, along with Cx26, Cx32 and Cx39 in other musculoskeletal tissues. Here, we discuss the basic structure of gap junctions and the role of the Cxs in musculoskeletal tissue, with special focus on Cx37. (AU)

Las conexinas (Cxs) son una familia de proteínas transmembrana que forman uniones en hendidura y hemicanales encargados de mediar la comunicación entre células vecinas y el respectivo medio extracelular en diferentes tejidos. La mayoría de los tejidos y células expresan una o más proteínas conexina, jugando un papel importante en la regulación de la proliferación celular, diferenciación, adhesión, migración y muerte celular, entre otras funciones. Además de actuar como un canal, las conexinas pueden propagar señales intracelulares a través del dominio C-terminal. La Cx43 es la conexina mas expresada y mejor estudiada en el tejido óseo y el músculo, aunque las Cx40, Cx45, Cx46, y mas recientemente Cx37, son también detectadas en el hueso. A su vez la expresión de la Cx26, Cx32 y Cx39 ha sido observada en otros tejidos músculoesqueléticos. En este manuscrito describimos la estructura básica de las uniones tipo gap y el papel que las Cxs, y en especial la Cx37, tienen en tejidos músculo-esqueléticos. (AU)

Influência da insulina sobre vias de sinalização envolvidas na peritonite provocada por inoculação de staphylococcus aureus em animais sadios e diabéticos / Influence of insulin on signaling pathways involved in peritonitis caused by inoculation of staphylococcus aureus in healthy and diabetic animals

Dentre tantas complicações do diabetes mellitus (DM), a infecção por bactérias comuns da microbiota superficial da pele como, por exemplo, a bactéria Gram-positiva Staphylococcus aureus, causadora de infecções como a peritonite, com altos índices de hospitalização e morte. A hipótese deste trabalho é a que o efeito da insulina na ativação das vias de sinalização MAPK, PKC e PI3K em peritonite induzida por S. aureus em animais diabéticos e não diabéticos possa regular a produção de citocinas. Foram utilizadas amostras de fígado, rim, linfonodos peritoniais e baço de animais oriundos de estudo anterior (Projeto FCF/USP-375), no qual animais diabéticos (aloxana, 42 mg/kg, i.v., 10 dias) e não-diabéticos com peritonite decorrente da infecção por S. aureus receberam uma dose de 4 UI e 1 UI de insulina NPH, respectivamente, por via subcutânea, 2 horas antes da infecção com S. aureus, e outras 3 doses de 2 UI e 0,5 UI às 17h00', respectivamente. A glicemia foi determinada no dia anterior, 10 dias após a injeção de aloxana e após os tratamentos com insulina. Em amostras de fígado, rim, linfonodo e baço dos animais supra citados foram avaliados a dosagem de citocinas (IL-1ß, IL-4, IL-10, TNF-α, CINC-1, CINC-2 e CINC-3) por ensaios de enzima-imunoensaio (ELISA); em homogenato de fígado foram avaliadas a expressão das moléculas das vias MAPK (fosfo P-38, fosfo ERK p42/44), PKC (fosfo PKC-α, fosfo PKC-δ) e PI3K (fosfo-AKT) pelo método de Western Blotting. Na avaliação do fígado, a insulina foi capaz de aumentar a concentração das citocinas IL-4 e TNF-α que apresentavam-se diminuídas em animais não diabéticos, em relação aos animais não diabéticos e não infectados, mas nos animais diabéticos, na infecção pela cepa N315, a insulina diminuiu a concentração de IL-4, que não estava alterada pela infecção, e não foi capaz de aumentar a concentração de IL-1ß que estava diminuída na infecção, em relação aos animais diabéticos e não infectados. Em linfonodos peritoniais de animais não diabéticos infectados pela cepa N315, a insulina diminuiu a produção de IL-1ß e IL-10, que não estavam alteradas na infecção, e diminuiu a concentração de IL-4, que estava aumentada na infecção, em relação aos animais não diabéticos e não infectados; em animais diabéticos, a insulina diminuiu a produção das citocinas IL-1ß e CINC-1, que estavam aumentadas, e aumentou a concentração de IL-10, que estava diminuída na infecção com a cepa N315, mas baixou a concentração de IL-4, em relação aos animais infectados, e na infecção pela cepa ATCC, a insulina aumentou a produção de IL-1ß, CINC-1 e CINC-3 dos animais tratados, em relação aos infectados e não tratados. Em baço, a insulina diminuiu a produção de IL-10 na infecção pela cepa ATCC tanto em animais não diabéticos quanto em animais diabéticos e, nesse último grupo, também aumentou a produção de CINC-3 em relação aos animais diabéticos não infectados; na infecção com a cepa N315, a insulina não aumentou a concentração de IL-1ß e TNF-α, que estavam diminuídas na infecção. Em rim, não houveram alterações significativas na produção de citocinas na infecção com nenhuma das cepas estudadas, nem para os grupos diabéticos, nem para os não diabéticos. Verificou-se que os animais diabéticos apresentam maior alteração tanto nas vias de sinalização estudadas quando na produção de citocinas pró-inflamatórias, quando comparados aos animais não diabéticos, na infecção por ambas as cepas de S. aureus estudadas. Assim, os resultados obtidos sugerem que o tratamento com insulina possa modular parcialmente a produção das citocinas IL-1ß, TNF-α e IL-10 no fígado e nos linfonodos peritoniais dos animais infectados principalmente pela cepa N315 de S.aureus, modulando parcialmente a expressão das moléculas da via de sinalização (MAPK e PKC), envolvidas na produção dessas citocinas

Among so many complications of diabetes mellitus (DM), infection by common bacteria of the superficial microbiota of the skin, for example, a gram-positive bacteria Staphylococcus aureus, causing infections like peritonitis, with high rates of hospitalization and death. The hypothesis of this study is that the effect of insulin on the activation of MAPK, PKC and PI3K signaling pathways in peritonitis induced by S. aureus in diabetic and non-diabetic animals may regulate the production of proinflammatory cytokines. Liver, kidney, peritonial lymph nodes and spleen samples of animals from the previous study (FCF / USP-375 Project) were used in this project; diabetic animals (alloxan, 42 mg / kg, iv, 10 days) and non-diabetic animals with peritonitis due to S. aureus infection received one dose of 4 IU and 1 IU of NPH insulin, respectively, subcutaneously, 2 hours before infection with S. aureus, and another 3 doses of 2 IU and 0.5 IU at 5:00 p.m., respectively. Blood glucose was determined the day before, 10 days after alloxan injection and after insulin treatments. In the liver, kidney, lymph node and spleen samples of the above-mentioned animals the cytokines (IL-1ß, IL-4, IL-10, TNF-α, CINC- 2 and CINC-3) by enzyme-immunoassay (ELISA) assays; we avaliated, by Western Blotting, the signaling pathways MAPK (phospho-P-38, phospho ERK p42 / 44), PKC (phospho PKC-α and phospho PKC-δ) and PI3K (phospho AKT) in liver, insulin was able to increase the concentration of cytokines IL-4 and TNF-α that were decreased in non-diabetic animals, in relation to non-diabetic and non-infected animals, but in diabetic animals, in strain N315, insulin decreased the concentration of IL-4, which was not altered by the infection, and was not able to increase the concentration of IL-1ß that was decreased in infection, relative to diabetic and uninfected animals. In peritonial lymph nodes from non-diabetic animals infected with the N315 strain, insulin decreased the production of IL-1ß and IL-10, which were not altered in the infection, and decreased the concentration of IL-4, which was increased in infection, in relation to non-diabetic and non-infected animals; in diabetic animals, insulin decreased IL-1ß and CINC-1 which were increased, and increased the concentration of IL-10, which was decreased in infection with strain N315, but decreased the concentration of IL-4 in Infected animals, and in infection by the ATCC strain, insulin increased the production of IL-1ß, CINC-1 and CINC-3 of treated animals over infected and untreated animals. In spleen, insulin decreased IL-10 production on infection by the ATCC strain in both non-diabetic and diabetic animals and, in this last group, also increased the production of CINC-3 in relation to uninfected diabetic animals; in infection with the N315 strain, insulin did not increased the concentration of IL-1ß and TNF-α, which were decreased in infection. In kidney, there were no significant changes in cytokine production in infection with any of the strains studied, neither for diabetic groups nor for non-diabetics. It was verified that diabetic animals present a greater alteration both in the signaling pathways studied and in the production of pro-inflammatory cytokines, when compared to non-diabetic animals, in the infection by both strains of S. aureus studied. Thus, the results suggest that insulin treatment may partially modulate the production of IL-1ß, TNF-α and IL-10 cytokines in the liver and in the peritonial lymph nodes of animals infected mainly with S. aureus strain N315, since they partially modulating the expression of signaling pathway molecules (MAPK and PKC), involved in the production of these cytokines