RESUMO
Sleep apnea syndrome (SAS) exposes cells throughout the body to intermittent hypoxia (IH). Intermittent hypoxia is a risk factor not only for hypertension and insulin resistance but also for vascular dysfunction. We have reported correlations between IH, insulin resistance and hypertension. However, the details of why IH leads to vascular dysfunction remain unclear. In this study, we investigated inflammation-related transcripts in vascular endothelial cells (human HUEhT-1 and mouse UV2) exposed to IH by real-time RT-PCR and found that intercellular adhesion molecule-1 (ICAM-1) and endothelial cell-specific molecule-1 (ESM1) mRNAs were significantly increased. ELISA confirmed that, in the UV2 cell medium, ICAM-1 and ESM1 were significantly increased by IH. However, the promoter activities of ICAM-1 and ESM1 were not upregulated. On the other hand, IH treatment significantly decreased microRNA (miR)-181a1 in IH-treated cells. The introduction of miR-181a1 mimic but not miR-181a1 mimic NC abolished the IH-induced upregulation of Ican-1 and ESM1. These results indicated that ICAM-1 and ESM1 were upregulated by IH via the IH-induced downregulation of miR-181a1 in vascular endothelial cells and suggested that SAS patients developed atherosclerosis via the IH-induced upregulation of ICAM-1 and ESM1.
Assuntos
Hipertensão , Resistência à Insulina , MicroRNAs , Animais , Humanos , Camundongos , Regulação para Baixo , Células Endoteliais/metabolismo , Hipóxia/metabolismo , Molécula 1 de Adesão Intercelular/genética , MicroRNAs/genética , Proteínas de Neoplasias/genética , Proteoglicanas/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Sleep apnoea syndrome is characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia [IH]) and is a risk factor for insulin resistance/Type 2 diabetes. The induction of insulin resistance in skeletal muscle is a key phenomenon to develop diabetes. However, the mechanisms linking IH stress and insulin resistance remain elusive. We exposed human RD and mouse C2C12 muscle cells to normoxia or IH and measured their mRNA levels by real-time RT-PCR. We found that IH significantly increased the mRNA and protein levels of muscle-derived insulin resistance-factors (myokines) such as IL-8, osteonectin (ON), and myonectin (MN) in muscle cells. We further analysed the IH-induced expression mechanisms of IL-8, ON, and MN genes in muscle cells. Deletion analyses of the human myokine promoter(s) revealed that the regions -152 to -151 in IL-8, -105 to -99 in ON, and - 3741 to -3738 in MN promoters were responsible for the activation by IH in RD cells. The promoters contain consensus transcription factor binding sequences for OCT1 in IL-8 and MN promoters, and for NRF2 in ON promoter, respectively. The introduction of siRNA for OCT1 abolished the IH-induced expression(s) of IL-8 and MN and siRNA for NRF2 abolished the IH-induced expression of ON.
Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Animais , Humanos , Camundongos , Hipóxia/genética , Hipóxia/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Osteonectina/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Regulação para Cima/genéticaRESUMO
Sleep apnea syndrome (SAS) is characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia [IH]), and is a risk factor for cardiovascular disease (CVD) and insulin resistance/Type 2 diabetes. However, the mechanisms linking IH stress and CVD remain elusive. We exposed rat H9c2 and mouse P19.CL6 cardiomyocytes to experimental IH or normoxia for 24 h to analyze the mRNA expression of several cardiomyokines. We found that the mRNA levels of regenerating gene IV (Reg IV) and hepatocyte growth factor (Hgf) in H9c2 and P19.CL6 cardiomyocytes were significantly increased by IH, whereas the promoter activities of the genes were not increased. A target mRNA search of microRNA (miR)s revealed that rat and mouse mRNAs have a potential target sequence for miR-499. The miR-499 level of IH-treated cells was significantly decreased compared to normoxia-treated cells. MiR-499 mimic and non-specific control RNA (miR-499 mimic NC) were introduced into P19.CL6 cells, and the IH-induced upregulation of the genes was abolished by introduction of the miR-499 mimic, but not by the miR-499 mimic NC. These results indicate that IH stress downregulates the miR-499 in cardiomyocytes, resulting in increased levels of Reg IV and Hgf mRNAs, leading to the protection of cardiomyocytes in SAS patients.
Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , MicroRNAs , Ratos , Camundongos , Animais , Miócitos Cardíacos/metabolismo , Regulação para Cima , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Crescimento de Hepatócito/genética , Fator de Crescimento de Hepatócito/metabolismo , Regulação para Baixo/genética , Hipóxia Celular/genética , Diabetes Mellitus Tipo 2/metabolismo , Hipóxia/genética , Hipóxia/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Oxigênio/metabolismo , Doenças Cardiovasculares/metabolismoRESUMO
The pathophysiology of inflammatory bowel diseases (IBD) reflects a balance between mucosal injury and reparative mechanisms. Some regenerating gene (Reg) family members (REG Iα, REG Iß and REG IV) are expressed in Crohn's disease (CD) and ulcerative colitis (UC) and involved as proliferative mucosal factors in IBD. We revealed that REG Iα and REG Iß were induced in cell culture system by IL-6/IL-22. Although REG IV was upregulated in IBD biopsy samples, the upregulation of REG IV was not at all induced in cell culture by autoimmune-related cytokines such as IL-6, IL-22 and TNFα. Here, we analysed REG IV expression in LS-174 T and HT-29 human intestinal epithelial cells by real-time RT-PCR and elisa. REG IV expression was induced by lipopolysaccharide (LPS). However, LPS did not activate REG IV promoter activity. As the LPS-induced upregulation of REG IV was considered to be regulated post-transcriptionally, we searched targeted microRNA (miR), which revealed that REG IV mRNA has a potential target sequence for miR-24. We measured the miR-24 level of LPS-treated cells and found that the level was significantly lower. The LPS-induced increase of REG IV mRNA was abolished by the introduction of miR-24 mimic but not by non-specific control RNA.
Assuntos
Colite Ulcerativa , Doenças Inflamatórias Intestinais , MicroRNAs , Proteínas Associadas a Pancreatite/genética , Colite Ulcerativa/patologia , Regulação para Baixo/genética , Células Epiteliais/metabolismo , Humanos , Doenças Inflamatórias Intestinais/patologia , Interleucina-6/metabolismo , Mucosa Intestinal/metabolismo , Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/farmacologia , Litostatina/genética , Litostatina/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Mensageiro/metabolismo , Regulação para Cima/genéticaRESUMO
Sleep apnea syndrome (SAS) is characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia, IH), and it is a risk factor for cardiovascular disease (CVD) and insulin resistance/type 2 diabetes. However, the mechanisms linking IH stress and CVD remain elusive. We exposed rat H9c2 and mouse P19.CL6 cardiomyocytes to experimental IH or normoxia for 24 h to analyze the mRNA expression of the components of Cd38-cyclic ADP-ribose (cADPR) signaling. We found that the mRNA levels of cluster of differentiation 38 (Cd38), type 2 ryanodine receptor (Ryr2), and FK506-binding protein 12.6 (Fkbp12.6) in H9c2 and P19.CL6 cardiomyocytes were significantly decreased by IH, whereas the promoter activities of these genes were not decreased. By contrast, the expression of phosphatase and tensin homolog deleted from chromosome 10 (Pten) was upregulated in IH-treated cells. The small interfering RNA for Pten (siPten) and a non-specific control RNA were introduced into the H9c2 cells. The IH-induced downregulation of Cd38, Ryr2, and Fkbp12.6 was abolished by the introduction of the siPten, but not by the control RNA. These results indicate that IH stress upregulated the Pten in cardiomyocytes, resulting in the decreased mRNA levels of Cd38, Ryr2, and Fkbp12.6, leading to the inhibition of cardiomyocyte functions in SAS patients.
Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , ADP-Ribosil Ciclase/genética , ADP-Ribosil Ciclase 1 , Animais , Sinalização do Cálcio , Doenças Cardiovasculares/metabolismo , ADP-Ribose Cíclica/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Regulação para Baixo , Hipóxia/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Miócitos Cardíacos/metabolismo , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Regulação para CimaRESUMO
Sleep apnea syndrome (SAS), characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia (IH)), is a risk factor for hypertension and insulin resistance. We report a correlation between IH and insulin resistance/diabetes. However, the reason why hypertension is induced by IH is elusive. Here, we investigated the effect of IH on the expression of catecholamine-metabolizing enzymes using an in vitro IH system. Human and mouse neuroblastoma cells (NB-1 and Neuro-2a) were exposed to IH or normoxia for 24 h. Real-time RT-PCR revealed that IH significantly increased the mRNA levels of dopamine ß-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT) in both NB-1 and Neuro-2a. Western blot showed that the expression of DBH and PNMT in the NB-1 cells was significantly increased by IH. Reporter assays revealed that promoter activities of DBH and PNMT were not increased by IH. The miR-375 level of IH-treated cells was significantly decreased relative to that of normoxia-treated cells. The IH-induced up-regulation of DBH and PNMT was abolished by the introduction of the miR-375 mimic, but not by the control RNA. These results indicate that IH stress increases levels of DBH and PNMT via the inhibition of miR-375-mediated mRNA degradation, potentially playing a role in the emergence of hypertension in SAS patients.
Assuntos
Hipertensão , Resistência à Insulina , MicroRNAs , Neuroblastoma , Animais , Dopamina beta-Hidroxilase/metabolismo , Humanos , Hipóxia/genética , Camundongos , MicroRNAs/genética , Neuroblastoma/genética , Feniletanolamina N-Metiltransferase/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Sleep apnea syndrome is characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia [IH]), and it is a known risk factor for hypertension. The upregulation of the renin-angiotensin system has been reported in IH, and the correlation between renin and CD38 has been noted. We exposed human HEK293 and mouse As4.1 renal cells to experimental IH or normoxia for 24 h and then measured the mRNA levels using a real-time reverse transcription polymerase chain reaction. The mRNA levels of Renin (Ren) and Cd38 were significantly increased by IH, indicating that they could be involved in the CD38-cyclic ADP-ribose signaling pathway. We next investigated the promotor activities of both genes, which were not increased by IH. Yet, a target mRNA search of the microRNA (miRNA) revealed both mRNAs to have a potential target sequence for miR-203. The miR-203 level of the IH-treated cells was significantly decreased when compared with the normoxia-treated cells. The IH-induced upregulation of the genes was abolished by the introduction of the miR-203 mimic, but not the miR-203 mimic NC negative control. These results indicate that IH stress downregulates the miR-203 in renin-producing cells, thereby resulting in increased mRNA levels of Ren and Cd38, which leads to hypertension.
Assuntos
ADP-Ribosil Ciclase 1/genética , Regulação para Baixo/genética , Hipóxia/genética , MicroRNAs/genética , Renina/genética , Regulação para Cima/genética , ADP-Ribosil Ciclase 1/metabolismo , Animais , ADP-Ribose Cíclica/análogos & derivados , ADP-Ribose Cíclica/metabolismo , Células HEK293 , Humanos , Camundongos , MicroRNAs/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Interferente Pequeno/metabolismo , Renina/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismoRESUMO
Preeclampsia/hypertensive disorders of pregnancy (PE/HDP) is a serious and potentially life-threatening disease. Recently, PE/HDP has been considered to cause adipose tissue inflammation, but the detailed mechanism remains unknown. We exposed human primary cultured adipocytes with serum from PE/HDP and healthy controls for 24 h, and analyzed mRNA expression of several adipokines, cytokines, and ligands of the receptor for advanced glycation endproducts (RAGE). We found that the mRNA levels of interleukin-6 (IL-6), C-C motif chemokine ligand 2 (CCL2), high mobility group box 1 (HMGB1), and RAGE were significantly increased by the addition of PE/HDP serum. Among RAGE ligands, advanced glycation endproducts (AGE) and HMGB1 increased mRNA levels of IL-6 and CCL2 in SW872 human adipocytes and mouse 3T3-L1 cells. The introduction of small interfering RNA for RAGE (siRAGE) into SW872 cells abolished the AGE- and HMGB1-induced up-regulation of IL-6 and CCL2. In addition, lipopolysaccharide (LPS), a ligand of RAGE, increased the expression of IL-6 and CCL2 and siRAGE attenuated the LPS-induced expression of IL-6 and CCL2. These results strongly suggest that the elevated AGE, HMGB1, and LPS in pregnant women up-regulate the expression of IL-6 and CCL2 via the RAGE system, leading to systemic inflammation such as PE/HDP.
Assuntos
Adipócitos/metabolismo , Hipertensão Induzida pela Gravidez/sangue , Pré-Eclâmpsia/sangue , Receptor para Produtos Finais de Glicação Avançada/genética , Soro/química , Células 3T3-L1 , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Adulto , Animais , Linhagem Celular Tumoral , Células Cultivadas , Quimiocina CCL2/genética , Meios de Cultura/química , Meios de Cultura/farmacologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Proteína HMGB1/genética , Humanos , Interleucina-6/genética , Camundongos , Gravidez , Interferência de RNARESUMO
Sleep apnea syndrome (SAS), characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia [IH]), is a risk factor for insulin resistance. Recently, IH is considered to independently cause adipose tissue inflammation/dysfunction, leading to worsening insulin resistance; however, the detailed mechanism remains unknown. We exposed mouse 3T3-L1 and human SW872 adipocytes to experimental IH or normoxia for 24 h, and analyzed mRNA expression of several adipokines. We found that the mRNA levels of RETN, TNFα, and CCL2 in SW872 and 3T3-L1 adipocytes were significantly increased by IH, whereas the promoter activities of these genes were not increased. A target mRNA search of microRNA (miR)s revealed that all human mRNAs have a potential target sequence for miR-452. The miR-452 level of IH-treated cells was significantly decreased compared to normoxia-treated cells. MiR-452 mimic and non-specific control RNA (miR-452 mimic NC) were introduced into SW872 cells, and the IH-induced up-regulation of the genes was abolished by introduction of the miR-452 mimic but not by the miR-452 mimic NC. These results indicate that IH stress down-regulates the miR-452 in adipocytes, resulting in increased levels of RETN, TNFα, and CCL2 mRNAs, leading to insulin resistance in SAS patients.
Assuntos
Adipócitos/metabolismo , Quimiocina CCL2/genética , Regulação da Expressão Gênica , MicroRNAs/genética , Interferência de RNA , Resistina/genética , Fator de Necrose Tumoral alfa/genética , Animais , Hipóxia Celular/genética , Linhagem Celular Tumoral , Quimiocina CCL2/metabolismo , Humanos , Camundongos , Regiões Promotoras Genéticas , Resistina/metabolismo , Apneia Obstrutiva do Sono/genética , Apneia Obstrutiva do Sono/metabolismo , Ativação Transcricional , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The patients with sleep apnea syndrome are exposed to intermittent hypoxia (IH) during sleep. We previously demonstrated the IH-induced up-regulation of the mRNA levels of anorexigenic peptides proopiomelanocortin (POMC), and cocaine- and amphetamine-regulated transcript (CART) in human neuronal cells. Appetite is regulated not only by the central nervous system but also by the peptides from gastrointestinal tract. Here, we investigated the effects of IH on the gene expression(s) of appetite-inhibiting gut hormones. Human enteroendocrine Caco-2 and mouse STC-1 cells were exposed to IH [64 cycles of 5 min hypoxia (1% O2) and 10 min normoxia (21% O2)] or normoxia for 24 h. Real-time RT-PCR revealed that IH significantly increased the mRNA levels of peptide YY (PYY), glucagon-like peptide-1 (GLP-1), and neurotensin (NTS) in Caco-2 and STC-1 cells. ELISA showed that the concentrations of PYY, GLP-1, and NTS in the culture medium were significantly increased by IH. The mRNA levels of PYY, GLP-1, and NTS were significantly up-regulated even in normoxia by Trichostatin A (TSA) and were significantly decreased even in IH by 5-azacytidine (5AZC), suggesting that IH increases PYY, GLP-1, and NTS mRNAs via alterations in the chromatin structure in enteroendocrine cells. IH might have an anorexigenic influence on the enteric nervous system.
Assuntos
Células Enteroendócrinas/metabolismo , Peptídeo 1 Semelhante ao Glucagon/genética , Hipóxia/genética , Neurotensina/genética , Peptídeo YY/genética , Regulação para Cima , Animais , Células CACO-2 , Hipóxia Celular , Linhagem Celular , Humanos , Camundongos , RNA Mensageiro/genéticaRESUMO
Patients with obstructive sleep apnea (OSA) experience repetitive episodes of desaturation and resaturation of blood oxygen (known as intermittent hypoxia or IH), during sleep. We showed previously that IH induced excessive proliferation of rat vascular smooth muscle cells through upregulation of members of the epidermal growth factor family, especially epiregulin (EREG), and the erbB2 receptor. In this study, we exposed human coronary artery smooth muscle cells to IH and found that IH significantly increased the expression of EREG. IH increased the production of interleukin-6 (IL-6) in smooth muscle cells, and the addition of IL-6 induced EREG expression. Small interfering RNA for IL-6 or IL-6 receptor attenuated the IH-induced increase in EREG. IL-6 may play a pivotal role in EREG upregulation by IH and consequently OSA-related atherosclerosis.
RESUMO
The pathophysiology of inflammatory bowel disease (IBD) reflects a balance between mucosal injury and reparative mechanisms. Some regenerating gene (Reg) family members have been reported to be expressed in Crohn's disease (CD) and ulcerative colitis (UC) and to be involved as proliferative mucosal factors in IBD. However, expression of all the REG family genes in IBD is still unclear. Here, we analyzed expression of all the REG family genes (REGIα, REGIß, REG III, HIP/PAP, and REG IV) in biopsy specimens of UC and CD by real-time RT-PCR. REG Iα, REG Iß, and REG IV genes were overexpressed in CD samples. REG IV gene was also overexpressed in UC samples. We further analyzed the expression mechanisms of REG Iα, REG Iß, and REG IV genes in LS-174T and HT-29 human colonic epithelial cells. The expression of REG Iα was significantly induced by IL-6 or IL-22, and REG Iß was induced by IL-22. Deletion analyses revealed that three regions (- 220~- 211, - 179~- 156, and - 146~- 130) in REG Iα and the region (- 274~- 260) in REG Iß promoter were responsible for the activation by IL-22/IL-6. The promoters contain consensus transcription factor binding sequences for MZF1, RTEF1/TEAD4, and STAT3 in REG Iα, and HLTF/FOXN2F in REG Iß, respectively. The introduction of siRNA for MZF1, RTEF1/TEAD4, STAT3, and HLTF/FOXN2F abolished the transcription of REG Iα and REG Iß. The gene activation mechanisms of REG Iα/REG Iß may play a role in colon mucosal regeneration in IBD.
Assuntos
Doenças Inflamatórias Intestinais/genética , Fatores de Transcrição/genética , Linhagem Celular Tumoral , Colo/metabolismo , Células Epiteliais/metabolismo , Células HT29 , Humanos , Mucosa Intestinal/metabolismo , Regiões Promotoras Genéticas/genéticaRESUMO
Sleep apnea syndrome (SAS) is characterized by intermittent hypoxia (IH) during sleep. SAS and obesity are strongly related to each other. Here, we investigated the effect of IH on the expression of major appetite regulatory genes in human neuronal cells. We exposed NB-1, SH-SY5Y, and SK-N-SH human neuronal cells to IH (64 cycles of 5â¯min hypoxia and 10â¯min normoxia), normoxia, or sustained hypoxia for 24â¯h and measured the mRNA levels of proopiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART), galanin, galanin-like peptide, ghrelin, pyroglutamylated RFamide peptide, agouti-related peptide, neuropeptide Y, and melanocortin 4 receptor by real-time RT-PCR. IH significantly increased the mRNA levels of POMC and CART in all the neuronal cells. Deletion analysis revealed that the -705 to -686 promoter region of POMC and the -950 to -929 region of CART were essential for the IH-induced promoter activity. As possible GATA factor binding sequences were found in the two regions, we performed real-time RT-PCR to determine which GATA family members were expressed and found that GATA2 and GATA3 mRNAs were predominantly expressed. Therefore, we introduced siRNAs against GATA2 and GATA3 into NB-1 cells and found that GATA2 and GATA3 siRNAs abolished the IH-induced up-regulation of both POMC and CART mRNAs. These results indicate that IH stress up-regulates the mRNA levels of anorexigenic peptides, POMC and CART, in human neuronal cells via GATA2 and GATA3. IH can have an anorexigenic effect on SAS patients through the transcriptional activation of POMC and CART in the central nervous system.
Assuntos
Fator de Transcrição GATA2/metabolismo , Fator de Transcrição GATA3/metabolismo , Regulação da Expressão Gênica , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Pró-Opiomelanocortina/metabolismo , RNA Mensageiro/metabolismo , Núcleo Arqueado do Hipotálamo/metabolismo , Núcleo Arqueado do Hipotálamo/patologia , Sítios de Ligação , Hipóxia Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Fator de Transcrição GATA2/antagonistas & inibidores , Fator de Transcrição GATA2/química , Fator de Transcrição GATA2/genética , Fator de Transcrição GATA3/antagonistas & inibidores , Fator de Transcrição GATA3/química , Fator de Transcrição GATA3/genética , Deleção de Genes , Genes Reporter , Humanos , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Neurônios/patologia , Pró-Opiomelanocortina/química , Pró-Opiomelanocortina/genética , Regiões Promotoras Genéticas , Síndromes da Apneia do Sono/metabolismo , Síndromes da Apneia do Sono/patologia , Fatores de Tempo , Regulação para CimaRESUMO
The pathophysiology of inflammatory bowel disease (IBD) reflects a balance between mucosal injury and reparative mechanisms. Some regenerating gene (Reg) family members have been reported to be expressed in Crohn's disease (CD) and ulcerative colitis (UC) and to be involved as proliferative mucosal factors in IBD. However, expression of all REG family genes in IBD is still unclear. Here, we analyzed expression of all REG family genes (REG Iα, REG Iß, REG III, HIP/PAP, and REG IV) in biopsy specimens of UC and CD by real-time RT-PCR. REG Iα, REG Iß, and REG IV genes were overexpressed in CD samples. REG IV gene was also overexpressed in UC samples. We further analyzed the expression mechanisms of REG Iα, REG Iß, and REG IV genes in human colon cells. The expression of REG Iα was significantly induced by IL-6 or IL-22, and REG Iß was induced by IL-22. Deletion analyses revealed that three regions (- 220 to - 211, - 179 to - 156, and - 146 to - 130) in REG Iα and the region (- 274 to- 260) in REG Iß promoter were responsible for the activation by IL-22/IL-6. The promoters contain consensus transcription factor binding sequences for MZF1, RTEF1/TEAD4, and STAT3 in REG Iα, and HLTF/FOXN2F in REG Iß, respectively. The introduction of siRNAs for MZF1, RTEF1/TEAD4, STAT3, and HLTF/FOXN2F abolished the transcription of REG Iα and REG Iß. The gene activation mechanisms of REG Iα/REG Iß may play a role in colon mucosal regeneration in IBD.
RESUMO
AIMS: Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, possess pleiotropic effects that have been extended to modulation of various cellular behaviors. This study aimed to examine whether statins modulate vascular endothelial growth factor A (VEGF-A) expression in human retinal pigment epithelium (RPE) cells. MAIN METHODS: Human RPE cells (h1RPE7), damaged by hydroquinone (HQ) + advanced glycation endproducts (AGE) in an in vitro AMD model, were treated with atorvastatin or lovastatin for 24 h. The expression of VEGF-A and receptor for AGE (RAGE) was evaluated by real-time RT-PCR. VEGF-A secretion was measured by ELISA. To investigate the impact of RAGE on VEGF-A expression, small interfering RNA (siRNA) for RAGE (siRAGE) was introduced into h1RPE7 cells and VEGF-A expression was measured by real-time RT-PCR. Deletions of VEGF-A and RAGE promoters were performed and transcriptional activities were measured after the addition of statins to HQ + AGE-damaged RPE cells. KEY FINDINGS: The mRNA levels of VEGF-A and RAGE and the levels of VEGF-A in the culture medium were increased by HQ + AGE. Both atorvastatin and lovastatin attenuated HQ + AGE-induced VEGF-A and RAGE expression. These statins also decreased VEGF-A levels in the culture medium. RNA interference of RAGE attenuated the up-regulation of VEGF-A in the HQ + AGE treated cells. The deletion analysis demonstrated that these statins attenuated RAGE promoter activation in HQ + AGE-damaged RPE cells. SIGNIFICANCE: Statins attenuated HQ + AGE-induced VEGF expression by decreasing RAGE expression. As VEGF is an important factor in developing wet AMD, statins could decrease the risk of wet-type AMD and be used as preventive medicines.
RESUMO
Sleep apnea syndrome is characterized by recurrent episodes of oxygen desaturation and reoxygenation (intermittent hypoxia [IH]) and is a risk factor for insulin resistance/type 2 diabetes. However, the mechanisms linking IH stress and insulin resistance remain elusive. We exposed human hepatocytes (JHH5, JHH7, and HepG2) to experimental IH or normoxia for 24 h, measured mRNA levels by real-time reverse transcription polymerase chain reaction (RT-PCR), and found that IH significantly increased the mRNA levels of selenoprotein P (SELENOP) - a hepatokine - and hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein (HIP/PAP) - one of REG (Regenerating gene) family. We next investigated promoter activities of both genes and discovered that they were not increased by IH. On the other hand, a target mRNA search of micro RNA (miRNA) revealed that both mRNAs have a potential target sequence for miR-203. The miR-203 level of IH-treated cells was significantly lower than that of normoxia-treated cells. Thus, we introduced miR-203 inhibitor and a non-specific control RNA (miR-203 inhibitor NC) into HepG2 cells and measured the mRNA levels of SELENOP and HIP/PAP. The IH-induced expression of SELENOP and HIP/PAP was abolished by the introduction of miR-203 inhibitor but not by miR-203 inhibitor NC. These results demonstrate that IH stress up-regulates the levels of SELENOP in human hepatocytes to accelerate insulin resistance and up-regulates the levels of HIP/PAP mRNAs to proliferate such hepatocytes, via the miR-203 mediated mechanism.
RESUMO
The regenerating gene, Reg, was originally isolated from a rat regenerating islet complementary DNA (cDNA) library, and its human homologue was named REG Iα. Recently, we reported that REG Iα messenger RNA (mRNA), as well as its product, was overexpressed in ductal epithelial cells in the salivary glands of Sjögren's syndrome patients. Furthermore, autoantibodies against REG Iα were found in the sera of Sjögren's syndrome patients, and the patients who were positive for the anti-REG Iα antibody showed significantly lower saliva secretion than antibody-negative patients. We found the mechanism of REG Iα induction in salivary ductal epithelial cells. Reporter plasmid containing REG Iα promoter (-1190/+26) upstream of a luciferase gene was introduced into human NS-SV-DC and rat A5 salivary ductal cells. The cells were treated with several cytokines (interleukin (IL)-6, IL-8, etc.), upregulated in Sjögren's syndrome salivary ducts, and the transcriptional activity was measured. IL-6 stimulation significantly enhanced the REG Iα promoter activity in both cells. Deletion analysis revealed that the -141â¼-117 region of the REG Iα gene was responsible for the promoter activation by IL-6, which contains a consensus sequence for signal transducer and activator of transcription (STAT) binding. The introduction of small interfering RNA for human STAT3 abolished IL-6-induced REG Iα transcription. These results indicated that IL-6 stimulation induced REG Iα transcription through STAT3 activation and binding to the REG Iα promoter in salivary ductal cells. This dependence of REG Iα induction upon IL-6/STAT in salivary duct epithelial cells may play an important role in the pathogenesis/progression of Sjögren's syndrome.
Assuntos
Autoantígenos/metabolismo , Células Epiteliais/imunologia , Interleucina-6/metabolismo , Litostatina/metabolismo , Fatores de Transcrição STAT/metabolismo , Ductos Salivares/patologia , Síndrome de Sjogren/imunologia , Animais , Autoanticorpos/metabolismo , Autoantígenos/imunologia , Feminino , Regulação da Expressão Gênica , Humanos , Litostatina/imunologia , Ratos , Transdução de SinaisRESUMO
BACKGROUNDS: Preterm birth (PTB)/admission to the neonatal intensive care unit (NICU) is a complex disorder associated with significant neonatal mortality and morbidity and long-term adverse health consequences. Multiple lines of evidence suggest that genetic factors play an important role in its etiology. AIM: Given the role of CD38 in term delivery through oxytocin (OXT) release, we hypothesized that OXT signaling may play a role in the etiology of PTB/admission to the NICU. This study was designed to identify genetic variation in the CD38-oxytocin pathway associated with PTB/admission to the NICU. METHODS: To identify common genetic variants predisposing individuals to PTB/admission to the NICU, we genotyped two single nucleotide polymorphisms (SNPs) in the CD38-oxytocin pathway in 63 case mothers, 55 control mothers, and 188 female volunteers in Nara Medical University Hospital, Japan. RESULTS: Maternal genetic effect analysis of the SNP genotype data revealed a significant association between an SNP in CD38 (rs1800561 (4693C>T): R140W), which was reported to be correlated with diabetes and autism, and the risk of NICU admission. On the other hand, an SNP in the oxytocin receptor (OXTR) (rs2254298) showed no correlation with the risk of NICU admission. CONCLUSION: Our study points to an association between maternal common polymorphisms in the CD38 (rs1800561) gene in Japanese women and susceptibility to PTB/admission to the NICU. Future studies with larger sample sizes are needed to confirm the findings of this study.
Assuntos
ADP-Ribosil Ciclase 1/genética , Polimorfismo de Nucleotídeo Único , Nascimento Prematuro/genética , Adulto , Sequência de Aminoácidos , Estudos de Casos e Controles , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Masculino , Dados de Sequência Molecular , Gravidez , Receptores de Ocitocina/genéticaRESUMO
Reg (Regenerating gene) gene was originally isolated from rat regenerating islets and its encoding protein was revealed as an autocrine/paracrine growth factor for ß cells. Rat Reg gene is activated in inflammatory conditions for ß cell regeneration. In human, although five functional REG family genes (REG Iα, REG Iß, REG III, HIP/PAP, and REG IV) were isolated, their expressions in ß cells under inflammatory conditions remained unclear. In this study, we found that combined addition of IL-6 and dexamethasone (Dx) induced REG Iα and REG Iß expression in human 1.1B4 ß cells. Promoter assay revealed that a signal transducer and activator of transcription- (STAT-) binding site in each promoter of REG Iα (TGCCGGGAA) and REG Iß (TGCCAGGAA) was essential for the IL-6+Dx-induced promoter activation. A Janus kinase 2 (JAK2) inhibitor significantly inhibited the IL-6+Dx-induced REG Iα and REG Iß transcription. Electrophoretic mobility shift assay and chromatin immunoprecipitation revealed that IL-6+Dx stimulation increased STAT3 binding to the REG Iα promoter. Furthermore, small interfering RNA-mediated targeting of STAT3 blocked the IL-6+Dx-induced expression of REG Iα and REG Iß. These results indicate that the expression of REG Iα and REG Iß should be upregulated in human ß cells under inflammatory conditions through the JAK/STAT pathway.
Assuntos
Glucocorticoides/farmacologia , Células Secretoras de Insulina/metabolismo , Interleucina-6/farmacologia , Janus Quinase 1/metabolismo , Litostatina/genética , Fatores de Transcrição STAT/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Proliferação de Células , Imunoprecipitação da Cromatina , Regulação da Expressão Gênica , Humanos , Inflamação , Ilhotas Pancreáticas/citologia , Proteínas Associadas a Pancreatite , Regiões Promotoras Genéticas , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Recombinantes/metabolismo , Fator de Transcrição STAT3/metabolismoRESUMO
The regenerating gene, Reg, was originally isolated from a rat regenerating islet cDNA library, and its human homolog was named REG Iα. Recently, we reported that REG Iα mRNA as well as its product were overexpressed in ductal epithelial cells in the minor salivary glands of Sjögren׳s syndrome (SS) patients. This study was undertaken to elucidate the role of cytokines and the subsequent intracellular mechanism for induction of REG Iα in the salivary glands of SS patients. We prepared a reporter plasmid containing REG Iα promoter (-1190/+26) upstream of a luciferase reporter gene. The promoter plasmid was introduced by lipofection into human NS-SV-DC and rat A5 salivary ductal cells. The cells were treated with interleukin (IL)-6, IL-8, and a combination of the two. Thereafter transcriptional activity of REG Iα was measured by luciferase assay. We found that IL-6 stimulation, but not IL-8, significantly enhanced the REG Iα promoter activity in salivary ductal cells. Deletion analysis revealed that the region of -141 to -117 of the REG Iα gene was responsible for the promoter activation by IL-6, which contains a consensus sequence for signal transduction and activation of transcription (STAT). The introduction of siRNA for human STAT3 abolished IL-6-induced REG Iα transcription. These results showed that IL-6 stimulation induced REG Iα transcription through STAT3 activation and binding to the consensus sequence of REG Iα promoter in salivary ductal cells. This IL-6/STAT dependent REG Iα induction might play a role in the pathogenesis of SS.