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BACKGROUND AND AIM: Although it is well established that hormones like glucagon stimulates gluconeogenesis via the PKA-mediated phosphorylation of CREB and dephosphorylation of the cAMP-regulated CREB coactivators CRTC2, the role of neural signals in the regulation of gluconeogenesis remains uncertain. METHODS AND RESULTS: Here, we characterize the noradrenergic bundle architecture in mouse liver; we show that the sympathoexcitation induced by acute cold exposure promotes hyperglycemia and upregulation of gluconeogenesis via triggering of the CREB/CRTC2 pathway. Following its induction by dephosphorylation, CRTC2 translocates to the nucleus and drives the transcription of key gluconeogenic genes. Rodents submitted to different models of sympathectomy or knockout of CRTC2 do not activate gluconeogenesis in response to cold. Norepinephrine directly acts in hepatocytes mainly through a Ca2+-dependent pathway that stimulates CREB/CRTC2, leading to activation of the gluconeogenic program. CONCLUSION: Our data demonstrate the importance of the CREB/CRTC2 pathway in mediating effects of hepatic sympathetic inputs on glucose homeostasis, providing new insights into the role of norepinephrine in health and disease.
Assuntos
Temperatura Baixa , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , Gluconeogênese , Fígado , Norepinefrina , Fatores de Transcrição , Animais , Gluconeogênese/fisiologia , Fígado/metabolismo , Camundongos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Masculino , Norepinefrina/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Neurônios Adrenérgicos/metabolismo , Neurônios Adrenérgicos/fisiologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/fisiologia , Hepatócitos/metabolismoRESUMO
Perfluorooctanesulfonic acid (PFOS) is a neurotoxic widespread organic contaminant which affects several brain functions including memory, motor coordination and social activity. PFOS has the ability to traverse the placenta and the blood brain barrier (BBB) and cause weight gain in female mice. It's also known that obesity and consumption of a high fat diet have negative effects on the brain, impairs cognition and increases the risk for the development of dementia. The combination effect of developmental exposure to PFOS and the intake of a high-fat diet (HFD) has not been explored. This study investigates the effect of PFOS and /or HFD on weight gain, behavior and transcriptomic and proteomic analysis of adult brain mice. We found that female mice exposed to PFOS alone showed an increase in weight, while HFD expectedly increased body weight. The combination of HFD and PFOS exacerbated generalized behavior such as time spent in the center and rearing, while PFOS alone impacted the distance travelled. These results suggest that PFOS exposure may promote hyperactivity. The combination of PFOS and HFD alter social behavior such as rearing and withdrawal. Although HFD interfered with memory retrieval, biomarkers of dementia did not change except for total Tau and phosphorylated Tau. Tau was impacted by either or both PFOS exposure and HFD. Consistent with behavioral observations, global cerebral transcriptomic analysis showed that PFOS exposure affects calcium signaling, MAPK pathways, ion transmembrane transport, and developmental processes. The combination of HFD with PFOS enhances the effect of PFOS in the brain and affects pathways related to ER stress, axon guidance and extension, and neural migration. Proteomic analysis showed that HFD enhances the impact of PFOS on inflammatory pathways, regulation of cell migration and proliferation, and MAPK signaling pathways. Overall, these data show that PFOS combined with HFD may reprogram the genome and modulate neuromotor development and may promote symptoms linked to attention deficit-hyperactivity disorders (ADHD) and autism spectrum disorders (ASD). Future work will be needed to confirm these connections.
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Ácidos Alcanossulfônicos , Demência , Fluorocarbonos , Transtornos do Neurodesenvolvimento , Gravidez , Camundongos , Animais , Feminino , Dieta Hiperlipídica/efeitos adversos , Proteômica , Aumento de Peso , Camundongos Endogâmicos C57BLRESUMO
Neutrophil extracellular traps (NETs) participate in the rapid inhibition and clearance of pathogens during infection; however, the molecular regulation of NET formation remains poorly understood. In the current study, we found that inhibition of the wild-type p53-induced phosphatase 1 (Wip1) significantly suppressed the activity of Staphylococcus aureus (S. aureus) and accelerated abscess healing in S. aureus-induced abscess model mice by enhancing NET formation. A Wip1 inhibitor significantly enhanced NET formation in mouse and human neutrophils in vitro. High-resolution mass spectrometry and biochemical assays demonstrated that Coro1a is a substrate of Wip1. Further experiments also revealed that Wip1 preferentially and directly interacts with phosphorylated Coro1a than compared to unphosphorylated inactivated Coro1a. The phosphorylated Ser426 site of Coro1a and the 28-90 aa domain of Wip1 are essential for the direct interaction of Coro1a and Wip1 and for Wip1 dephosphorylation of p-Coro1a Ser426. Wip1 deletion or inhibition in neutrophils significantly upregulated the phosphorylation of Coro1a-Ser426, which activated phospholipase C and subsequently the calcium pathway, the latter of which promoted NET formation after infection or lipopolysaccharide stimulation. This study revealed Coro1a to be a novel substrate of Wip1 and showed that Wip1 is a negative regulator of NET formation during infection. These results support the potential application of Wip1 inhibitors to treat bacterial infections.
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Armadilhas Extracelulares , Camundongos , Humanos , Animais , Proteína Fosfatase 2C/metabolismo , Armadilhas Extracelulares/metabolismo , Abscesso , Staphylococcus aureus/metabolismo , Neutrófilos/metabolismo , Proteínas dos MicrofilamentosRESUMO
The plasma membrane calcium pump (PMCA) is an important transporter that maintains intracellular calcium concentration ([Ca2+]i). It allows the calcium (Ca2+) from inside the cell to go out of the cell through the plasma membrane. For this, it cooperates with the proteins in the cell. The aim of this study is to demonstrate the effect of PMCA on intracellular calcium signaling in breast cancer cells. In this study, PMCA was inhibited by orthovanadate (OV), and changes in Calmodulin (CaM), Calcineurin (CaN) and cMyc proteins were demonstrated. Intracellular calcium accumulation was measured when PMCA was inhibited in MDA-MB-231 cells. At the same time, it was observed that the cell movement decreased with time. Over time, CaN and CaM were slightly suppressed, and cMyc protein was not expressed. As a result, when PMCA protein is targeted correctly in breast cancer cells, it has an indirect effect on cancer-promoting proteins.
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Neoplasias da Mama , Calmodulina , Neoplasias da Mama/metabolismo , Calcineurina/metabolismo , Cálcio/metabolismo , Sinalização do Cálcio , Calmodulina/metabolismo , Membrana Celular/metabolismo , Feminino , Humanos , Vanadatos/metabolismoRESUMO
The Wnt family of secreted glycolipo-proteins signals through multiple signal transduction pathways and is essential for embryonic development and organ development and homeostasis. The Wnt-pathways are conserved and critical in all metazoans. Wnt signaling pathways comprise the canonical Wnt/ß-catenin pathway and several non-canonical signaling branches, of which Wnt-Planar Cell Polarity (PCP) signaling and the Wnt/Calcium pathway have received the most attention and are best understood. nterestingly, all Wnt-pathways have a nuclear signaling branch and also can affect many cellular processes independent of its nuclear transcriptional regulation. Canonical Wnt/ß-catenin signaling is the most critical for a nuclear transcriptional response, in both development and disease, yet the mechanism(s) on how the "business end" of the pathway, ß-catenin, translocates to the nucleus to act as co-activator to the TCF/Lef transcription factor family still remains obscure. Here we discuss and compare the very different strategies on how the respective Wnt signaling pathways activate a nuclear transcriptional response. We also highlight some recent new insights into how ß-catenin is translocated to the nucleus via an IFT-A, Kinesin-2, and microtubule dependent mechanism and how this aspect of canonical Wnt-signaling uses ciliary proteins in a cilium independent manner, conserved between Drosophila and mammalian cells.
Assuntos
Via de Sinalização Wnt , beta Catenina , Animais , Núcleo Celular/metabolismo , Drosophila , Mamíferos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Wnt/metabolismo , beta Catenina/metabolismoRESUMO
Antiviral effectors such as natural killer (NK) cells have impaired functions in chronic hepatitis B (CHB) patients. The molecular mechanism responsible for this dysfunction remains poorly characterised. We show that decreased cytokine production capacity of peripheral NK cells from CHB patients was associated with reduced expression of NKp30 and CD16, and defective mTOR pathway activity. Transcriptome analysis of patients NK cells revealed an enrichment for transcripts expressed in exhausted T cells suggesting that NK cell dysfunction and T cell exhaustion employ common mechanisms. In particular, the transcription factor TOX and several of its targets were over-expressed in NK cells of CHB patients. This signature was predicted to be dependent on the calcium-associated transcription factor NFAT. Stimulation of the calcium-dependent pathway recapitulated features of NK cells from CHB patients. Thus, deregulated calcium signalling could be a central event in both T cell exhaustion and NK cell dysfunction occurring during chronic infections.
Assuntos
Fatores de Restrição Antivirais/imunologia , Hepatite B Crônica/imunologia , Células Matadoras Naturais/imunologia , Infecção Persistente/imunologia , Linfócitos T/imunologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
INTRODUCTION: Clinical studies have indicated a relationship between diabetic nephropathy (DN) and the incidence and prevalence of renal cell carcinoma (RCC). However, the mechanism linking diabetic nephropathy and renal cell carcinoma has not yet to be identified. METHODS: In this study, a total of 42 male Sprague Dawley (SD) rats were randomly assigned to a DN group (n=35) and a control group (n=7). All animals in the DN group were unilaterally nephrectomized and treated with streptozotocin with the development of blood glucose levels >16.7mmol/L and dominant proteinuria and were compared to controls without such changes. Histopathologic alterations in the kidneys were examined by HE staining and Ki-67 immunohistochemistry. Differentially expressed genes were identified and validated by RNA-seq and PCR. RESULTS: As the results, except for two rats that failed to develop the DN model and were excluded from the analysis, 33 rats in the DN group with overt signs of DN demonstrated significantly higher food and water intake, urine production, and urine protein and urinary protein/creatinine ratio than controls. Overall, 15.2% (n=5/33) of DN animals developed RCC while none tumors were observed in the control group (n=0/7). RNA-seq analysis in these animals indicated different TRPV5 gene expression and calcium pathway expression in DN animals with developing tumors, when compared with animals with no obvious tumors. In addition, DN animals diagnosed with RCC showed increased expression of GLUT2 and c-met, when compared to controls and DN animals without tumors. DISCUSSION: In conclusion, the disordered calcium metabolism, especially disturbed TRPV5 mediated Ca2+ signal, may have been related to the development of RCC in DN rats. Further studies related to the detailed mechanism are still needed.
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OBJECTIVES: The present review systematically summarized existing publications regarding the genetic associations between voltage-gated calcium channels (VGCCs) and autism spectrum disorder (ASD). METHODS: A comprehensive literature search was conducted to gather pertinent studies in three online databases. Two authors independently screened the included records based on the selection criteria. Discrepancies in each step were settled through discussions. RESULTS: From 1163 resulting searched articles, 28 were identified for inclusion. The most prominent among the VGCCs variants found in ASD were those falling within loci encoding the α subunits, CACNA1A, CACNA1B, CACNA1C, CACNA1D, CACNA1E, CACNA1F, CACNA1G, CACNA1H, and CACNA1I as well as those of their accessory subunits CACNB2, CACNA2D3, and CACNA2D4. Two signaling pathways, the IP3-Ca2+ pathway and the MAPK pathway, were identified as scaffolds that united genetic lesions into a consensus etiology of ASD. CONCLUSIONS: Evidence generated from this review supports the role of VGCC genetic variants in the pathogenesis of ASD, making it a promising therapeutic target. Future research should focus on the specific mechanism that connects VGCC genetic variants to the complex ASD phenotype.
Assuntos
Transtorno do Espectro Autista/genética , Canais de Cálcio/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Sinalização do Cálcio/genética , Humanos , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismoRESUMO
TOB1 participates in various kinds of cancers. However, its role in pancreatic cancer has rarely been reported. In this study, we explored the expression and mechanisms of TOB1 in regulating the malignant phenotype of pancreatic cancer cells. TOB1 expression was determined by data mining and immunohistochemistry (IHC), and its localization was observed by immunofluorescence. CCK-8 cell proliferation, colony formation, flow cytometric, transwell migration, and Western blot (WB) assays were used to examine how it impacts the malignant phenotype of pancreatic cancer. Furthermore, Foxa2 binding to TOB1 was tested by dual-luciferase reporter assays, and RNA-Seq was performed to identify signaling pathways. We found TOB1 was downregulated in pancreatic cancer tissues and was mainly located in the cytoplasm. TOB1 overexpression reduced the proliferation of K-Ras wild-type pancreatic cancer cells but made no difference to cell migration and invasion. Foxa2 overexpression significantly enhanced TOB1 promoter activity. Moreover, overexpressing TOB1 substantially enriched the calcium pathway in K-Ras wild-type pancreatic cancer cells. In conclusion, TOB1 may suppress the proliferation of K-Ras wild-type pancreatic cancer cells by regulating calcium pathway genes.
Assuntos
Regulação Neoplásica da Expressão Gênica , Fator 3-beta Nuclear de Hepatócito/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pancreáticas/genética , Proteínas Supressoras de Tumor/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Conjuntos de Dados como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pâncreas/patologia , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , RNA-Seq , Análise Serial de TecidosRESUMO
Accumulation of ß-amyloid (Aß) peptide and hyperphosphorylated tau in the brain is one of the pathological characteristics of Alzheimer's disease (AD) and attractive therapeutic targets in its treatment. In the present study, the cognitive ability of 4-month-old 3 × Tg-AD mice significantly improved after 40 days treatment with intraperitoneal injection of 2.25 mg/kg of SLOH, which is a multifunctional carbazole-based cyanine fluorophore. It reduced Aß deposition, tau levels and its hyperphosphorylation by modulating AKT and promoting protein phosphatase 2A activity in the brain as well as in the primary neurons of 3 × Tg-AD mice. Moreover, SLOH attenuated synaptic deficit both in vitro and in vivo by regulating the Ca2+/CaMKII/CREB signaling pathway. These findings strongly suggest that SLOH owns a high therapeutic potential to treat early onset AD.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Carbazóis/uso terapêutico , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Aprendizagem em Labirinto/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Encéfalo/metabolismo , Cálcio/metabolismo , Carbazóis/farmacologia , Cognição/efeitos dos fármacos , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos , Sinapses/metabolismo , Proteínas tau/metabolismoRESUMO
In adipocytes, intracellular Ca2+ and Mg2+ modulates physiological functions, such as insulin action and the secretion of adipokines. TRPM7 is a Ca2+ /Mg2+ -permeable non-selective cation channel. TRPM7 mRNA is highly expressed in adipose tissue, however, its functional expression in adipocytes remains to be elucidated. In this study, we demonstrated for the first time that TRPM7 was functionally expressed in both freshly isolated white adipocytes and in 3T3-L1 adipocytes differentiated from a 3T3-L1 pre-adipocyte cell line by whole-cell patch-clamp recordings. Consistent with known properties of TRPM7 current, the current in adipocytes was activated by the elimination of extracellular divalent cations and the reduction of intracellular free Mg2+ concentrations, and was inhibited by the TRPM7 inhibitors, 2-aminoethyl diphenylborinate (2-APB), hydrogen peroxide (H2 O2 ), N-methyl maleimide (NMM), NS8593, and 2-amino-2-[2-(4-octylphenyl)ethyl]-1,3-propanediol (FTY720). Treatment with small-interfering (si) RNA targeting TRPM7 resulted in a reduction in the current to 23 ± 7% of nontargeting siRNA-treated adipocytes. Moreover a TRPM7 activator, naltriben, increased the TRPM7-like current and [Ca2+ ]i in 3T3-L1 adipocytes but not in TRPM7-knockdown adipocytes. These findings indicate that TRPM7 is functionally expressed, and plays a role as a Ca2+ influx pathway in adipocytes.
Assuntos
Adipócitos/metabolismo , Cálcio/metabolismo , Canais de Cátion TRPM/metabolismo , Células 3T3-L1/metabolismo , Animais , Camundongos , Técnicas de Patch-Clamp , Canais de Cátion TRPM/genéticaRESUMO
Maintenance of self-tolerance of auto-reactive lymphocytes is a fundamental mechanism to prevent the onset of autoimmune diseases. Deciphering the mechanisms involved in the deregulations leading to tolerance disruption and autoimmunity is still a major area of interest to identify new therapeutic targets and options. Ca2+ signaling plays a major role in B cell normal development and is therefore finely tuned by B cell receptor (BCR)-dependent and independent pathways. Developmental changes in the characteristics of BCR-dependent Ca2+ signals as well as the modulation of basal intracellular concentration ([Ca2+]i) contribute strongly to self-tolerance maintaining mechanisms responsible for the physical or functional elimination of autoreactive B cells such as clonal deletion, receptor editing, and anergy. Implication of Ca2+ signals in B tolerance mechanisms mainly occurs through the specific activation of transcriptional programs depending on the amplitude, shape, and duration of Ca2+ signals. A large number of studies reported Ca2+ signaling defects in autoimmune pathology such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and primary SjÓ§gren's syndrome (pSS). However, the precise nature of the molecular events responsible for these deregulations is not fully understood. Moreover, the demonstration of a direct correlation between Ca2+ signaling defects and tolerance disruption is still lacking. The recent identification of proteins involved in B cell Ca2+ signals such as ORAI, stromal interaction molecule and transient receptor potential is opening new horizons for understanding Ca2+ signaling defects observed in autoimmune diseases and for proposing potentially new therapeutic solutions. This review aims to present an overview of the developmental evolution of BCR dependent Ca2+ signaling and to place this signaling pathway in the context of mechanisms involved in tolerance maintenance and breakdown.
Assuntos
Doenças Autoimunes/imunologia , Linfócitos B/fisiologia , Sinalização do Cálcio , Receptores de Antígenos de Linfócitos B/metabolismo , Animais , Autoantígenos/imunologia , Autoimunidade , Diferenciação Celular , Seleção Clonal Mediada por Antígeno , Humanos , Tolerância Imunológica , Ativação LinfocitáriaRESUMO
As shown in a large clinical prospective trial, inhibition of the renin-angiotensin system (RAS) can delay the onset of type 2 diabetes in high-risk individuals. We evaluated the beneficial effects of RAS inhibition on ß-cell function under glucotoxic conditions. Human islets from 13 donors were cultured in 5.5 mM (controls) or 16.7 mM glucose [high glucose (HG)] for 4 d with or without losartan (5 µM), a selective AT1R blocker, and/or U73122 (2 µM), a selective PLC inhibitor, during the last 2 d. HG induced RAS activation with overexpression of AT1R (P<0.05) and angiotensinogen (P<0.001) mRNAs. HG increased endoplasmic reticulum (ER) stress markers (P<0.001) such as GRP78, sXBP1, and ATF4 mRNAs and Grp78 protein levels (P<0.01). HG also decreased reticular calcium concentration (P<0.0001) and modified protein expressions of ER calcium pumps with reduction of SERCA2b (P<0.01) and increase of IP3R2 (P<0.05). Losartan prevented these deleterious effects and was associated with improved insulin secretion despite HG exposure. AT1R activation triggers the PLC-IP3-calcium pathway. Losartan prevented the increase of PLC ß1 and γ1 protein levels induced by HG (P<0.05). U73122 reproduced all the protective effects of losartan. AT1R blockade protects human islets from the deleterious effects of glucose through inhibition of the PLC-IP3-calcium pathway.