This study aims to explore the effects of arachidonic acid lipoxygenase metabolism in vascular calcification. We used 5/6 nephrectomy and high-phosphorus feeding to establish a model of vascular calcification in mice. Six weeks after nephrectomy surgery, vascular calcium content was measured, and Alizarin Red S and Von Kossa staining were applied to detect calcium deposition in aortic arch. Control aortas and calcified aortas were collected for mass spectrometry detection of arachidonic acid metabolites, and active molecules in lipoxygenase pathway were analyzed. Real-time quantitative PCR was used to detect changes in the expression of lipoxygenase in calcified aortas. Lipoxygenase inhibitor was used to clarify the effect of lipoxygenase metabolic pathways on vascular calcification. The results showed that 6 weeks after nephrectomy surgery, the aortic calcium content of the surgery group was significantly higher than that of the sham group (P < 0.05). Alizarin Red S staining and Von Kossa staining showed obvious calcium deposition in aortic arch from surgery group, indicating formation of vascular calcification. Nine arachidonic acid lipoxygenase metabolites were quantitated using liquid chromatography/mass spectrometry (LC-MS) analysis. The content of multiple metabolites (12-HETE, 11-HETE, 15-HETE, etc.) was significantly increased in calcified aortas, and the most abundant and up-regulated metabolite was 12-HETE. Furthermore, we examined the mRNA levels of metabolic enzymes that produce 12-HETE in calcified blood vessels and found the expression of arachidonate lipoxygenase-15 (Alox15) was increased. Blocking Alox15/12-HETE by Alox15 specific inhibitor PD146176 significantly decreased the plasma 12-HETE content, promoted calcium deposition in aortic arch and increased vascular calcium content. These results suggest that the metabolism of arachidonic acid lipoxygenase is activated in calcified aorta, and the Alox15/12-HETE signaling pathway may play a protective role in vascular calcification.
12-Hydroxy-5,8,10,14-eicosatetraenoic Acid ; Animals ; Arachidonate 12-Lipoxygenase ; Arachidonate 15-Lipoxygenase/metabolism* ; Arachidonic Acid ; Hydroxyeicosatetraenoic Acids ; Lipoxygenase/metabolism* ; Mice ; Signal Transduction ; Vascular Calcification

BACKGROUND AND OBJECTIVES: We determined the localization of leukocyte-type 12-lipoxygenase (L-12-LO) in murine nasal mucosa and to investigate the expression of L-12-LO according to the development of murine nasal mucosa. MATERIALS AND METHOD: Immunohistochemical staining was done on the nasal mucosa of mice at gestational days 16, 17, 18, and mice at postnatal days 1, 3, 7, 14, and adult mice. Alcian blue (pH 2.5)-periodic acid Schiff staining on murine nasal mucosa was performed. RESULTS: In murine nasal respiratory mucosa, the expression of L-12-LO was noted in ciliated epithelial cells, basal cells, serous acini, and secretory ducts, but it was not found in the mucous acini and goblet cells. In olfactory mucosa, the expression of L-12-LO was noted in the olfactory receptor cells, supporting cells, and basal cells. The expression in respiratory mucosa according to the development was strongly noticed from the gestational day 16 through postnatal day 7. The expression in postnatal day 14 and adult mice was weaker than in the previous time point. The expression in olfactory mucosa showed no difference throughout the developmental stage. CONCLUSION: As a result of this study, we found the exact localization of L-12-LO in murine nasal mucosa, and we also found the different expression of L-12-LO between the respiratory and olfactory mucosa. This fact suggests the possible involvement of L-12-LO in the development of murine respiratory mucosa.
Adult ; Alcian Blue ; Animals ; Arachidonate 12-Lipoxygenase* ; Epithelial Cells ; Goblet Cells ; Humans ; Immunohistochemistry ; Mice ; Nasal Mucosa* ; Olfactory Mucosa ; Respiratory Mucosa

OBJECTIVE: To explore the clinical and genetic characteristics of a pediatric patient suspected for Autosomal Recessive Congenital Ichthyosis (ARCI). METHODS: Clinical data of the patient was analyzed. Peripheral blood samples were collected from the patient and his parents for the extraction of genomic DNA. Next-generation sequencing (NGS) was then carried out. Candidate variants were confirmed by Sanger sequencing. A variety of bioinformatic tools including Mutation Taster, PROVEAN, and PolyPhen2 were used to predict the pathogenicity of the variants based on guidelines from the American College of Medical Genetics and Genomics (ACMG). RESULTS: The patient, a 1-month-and-7-day-old male, had presented with cutaneous erythema and fine scaling of the whole body. NGS revealed that he has harbored compound heterozygous variants c.1579G>A (p.Val527Met) (paternal) and c.923T>C (p.Leu308Pro) (maternal) of the ALOX12B gene. The former was known to be likely pathogenic, while the latter was unreported previously and categorized as "likely pathogenic" based on the ACMG guidelines. Based on the clinical and genetic findings, the patient was diagnosed with ARCI. CONCLUSION The c.1579G>A and c.923T>C variants of the ALOX12B genes probably underlay the ARCI in this patient. Above finding has enriched the spectrum of ALOX12B mutations and enabled molecular diagnosis of the patient, based on which genetic counseling and prenatal diagnosis may be provided.
Arachidonate 12-Lipoxygenase/genetics* ; Child ; Female ; Genes, Recessive ; Genetic Testing ; High-Throughput Nucleotide Sequencing ; Humans ; Ichthyosis, Lamellar/genetics* ; Male ; Mutation ; Pregnancy

Angiotensin II (Ang II) plays an important role in vascular hypertension. The role of the chemokine CCL5 on Ang II-induced activities in vascular smooth muscle cells (VSMCs) has not been studied. In this study, we elucidated the effect of CCL5 on Ang II-induced 12-lipoxygenase (LO) expression and cell proliferation in spontaneously hypertensive rats (SHR) VSMCs. CCL5 decreased Ang II-induced 12-LO mRNA expression and protein production, and it increased Ang II type 2 (AT2) receptor expression in SHR VSMCs. The inhibitory effect of CCL5 on Ang II-induced 12-LO mRNA expression was mediated through the AT2 receptor. Although treatment of CCL5 alone induced SHR VSMCs proliferation, CCL5 inhibited Ang II-induced VSMCs proliferation and PD123,319, an AT2 receptor antagonist, blocked the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation. Phosphorylation of p38 was detected in VSMCs treated with Ang II or CCL5 alone. But, decrease of p38 phosphorylation was detected in VSMCs treated with Ang II and CCL5 simultaneously (Ang II/CCL5) and PD123,319 increased p38 phosphorylation in VSMCs treated with Ang II/CCL5. Therefore, these results suggest that the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation is mediated by the AT2 receptor via p38 inactivation, and CCL5 may play a beneficial role in Ang II-induced vascular hypertension.
Angiotensin II ; Angiotensins ; Arachidonate 12-Lipoxygenase ; Cell Proliferation ; Chemokine CCL5 ; Down-Regulation ; Hypertension ; Muscle, Smooth, Vascular ; Phosphorylation ; Rats, Inbred SHR ; Receptor, Angiotensin, Type 2 ; RNA, Messenger

Apoptosis ; drug effects ; Arachidonate 12-Lipoxygenase ; analysis ; physiology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Enzyme Inhibitors ; pharmacology ; Flavanones ; pharmacology ; Humans ; Lipoxygenase Inhibitors ; Multiple Myeloma ; drug therapy ; pathology

BACKGROUND: We previously demonstrated remarkable differences in the expression of IL-8/CXCL8 in aortic tissues and vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) compared to VSMC from normotensive Wistar-Kyoto rats (WKY). In the present study, we investigated the direct effect of IL-8/CXCL8 on expression of 12-lipoxygenase (LO), a hypertensive modulator, in SHR VSMC. METHODS: Cultured aortic VSMC from SHR and WKY were used. Expression of 12-LO mRNA was determined by real-time polymerase chain reaction. Phosphorlyation of ERK1/2 and production of 12-LO and angiotensin II subtype 1 (AT1) receptor were assessed by Western blots. IL-8/CXCL8-stimulated DNA synthesis was determined by measuring incorporation of [3H]-thymidine. And effect of IL-8/CXCL8 on vascular tone was determined by phenylephrine-induced contraction of thoracic aortic rings. RESULTS: Treatment with IL-8/CXCL8 greatly increased 12-LO mRNA expression and protein production compared to treatment with angiotensin II. IL-8/CXCL8 also increased the expression of the AT1 receptor. The increase in 12-LO induced by IL-8/CXCL8 was inhibited by treatment with an AT1 receptor antagonist. The induction of 12-LO mRNA production and the proliferation of SHR VSMC by IL-8/CXCL8 was mediated by the ERK pathway. The proliferation of SHR VSMC and the vascular contraction in the thoracic aortic ring, both of which were induced by IL-8/CXCL8, were inhibited by baicalein, a 12-LO inhibitor. CONCLUSION: These results suggest that the potential role of IL-8/CXCL8 in hypertensive processes is likely mediated through the 12-LO pathway.
Angiotensin II ; Animals ; Arachidonate 12-Lipoxygenase ; Blotting, Western ; Contracts ; DNA ; Flavanones ; MAP Kinase Signaling System ; Muscle, Smooth, Vascular ; Rats ; Rats, Inbred SHR ; Real-Time Polymerase Chain Reaction ; RNA, Messenger

Endothelin-1 (ET-1) has been characterized as a potent vasoconstrictor secreted by the endothelium, and play a major role in the regulation of vascular tone. It has been also known to participate in inflammatory reactions. The production of ET-1 by macrophages during infection and inflammation is related to tissue perfusion and leukocyte extravasation. The aim of this study is to investigate the role of IL-8/CXCL8, as a major inflammatory chemokine, for ET-1 expression in macrophges. Expression of ET-1 mRNA in mouse peritoneal macrophages (PeM phi) was weaker than that in vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). However, expression of IL-8/CXCL8-induced ET-1 mRNA in PeM phi was much more stronger than that in SHR and WKY VSMCs. Maximum expression of ET-1 mRNA was observed at 50 ng/ml dose of IL-8/CXCL8 and occurred at 2 h after addition of IL-8/CXCL8. Expression of ET-1 by IL-8/CXCL8 was dependent on NF-kappaB activation and ERK1/2 phosphorylation. Baicalein, a 12-lipoxygenase (LO) inhibitor, inhibited the expression of IL-8/CXCL8-induced ET-1 mRNA. This inhibitory action of baicalein was mediated via ERK1/2 inactivation. Induction of 12-LO mRNA by IL-8/CXCL8 and expression of ET-1 mRNA by 12-LO metabolite, 12(S)-HETE were also detected. The expression of IL-8/CXCL8-induced ET-1 mRNA was not detected in PeM phi transfected with 12-LO siRNA. These results suggest that IL-8/CXCL8 can act as one of main inducers of ET-1 in vascular inflammatory reactions, and ET-1 expression by IL-8/CXCL8 is related to 12-LO pathway in PeM phi.
Animals ; Arachidonate 12-Lipoxygenase ; Endothelin-1 ; Endothelium ; Flavanones ; Inflammation ; Leukocytes ; Macrophages ; Macrophages, Peritoneal ; Mice ; Muscle, Smooth, Vascular ; NF-kappa B ; Perfusion ; Phosphorylation ; Rats ; Rats, Inbred SHR ; RNA, Messenger ; RNA, Small Interfering

BACKGROUND: Extracellular sulfatases (Sulfs), sulfatase 1 (Sulf1) and sulfatase 2 (Sulf2), play a pivotal role in cell signaling by remodeling the 6-O-sulfation of heparan sulfate proteoglycans on the cell surface. The present study examined the effects of Sulfs on angiotensin II (Ang II)-induced hypertensive mediator expression and vascular smooth muscle cells (VSMCs) proliferation in spontaneously hypertensive rats (SHR). METHODS: Ang II receptors, 12-lipoxygenase (12-LO), and endothelin-1 (ET-1) messenger RNA (mRNA) expressions in SHR VSMCs were analyzed by real-time polymerase chain reaction and Western blotting. VSMCs proliferation was determined by [³ H]-thymidine incorporation. RESULTS: Basal Sulfs mRNAs expression and enzyme activity were elevated in SHR VSMCs. However, Sulfs had no effect on the basal or Ang II-induced 12-LO and ET-1 mRNA expression in SHR VSMCs. The inhibition of Ang II-induced 12-LO and ET-1 expression by blockade of the Ang II type 2 receptor (AT₂ R) pathway was not observed in Sulf1 siRNA-transfected SHR VSMCs. However, Sulf2 did not affect the action of AT₂ R inhibitor on Ang II-induced 12-LO and ET-1 expression in SHR VSMCs. The down-regulation of Sulf1 induced a reduction of AT₂ R mRNA expression in SHR VSMCs. In addition, the inhibition of Ang II-induced VSMCs proliferation by blockade of the AT₂ R pathway was mediated by Sulf1 in SHR VSMCs. CONCLUSION: These findings suggest that extracellular sulfatase Sulf1 plays a modulatory role in the AT₂ R pathway that leads to an Ang II-induced hypertensive effects in SHR VSMCs.
Angiotensin II* ; Angiotensins* ; Arachidonate 12-Lipoxygenase ; Blotting, Western ; Down-Regulation ; Endothelin-1 ; Heparan Sulfate Proteoglycans ; Hypertension ; Muscle, Smooth, Vascular* ; Rats, Inbred SHR* ; Real-Time Polymerase Chain Reaction ; Receptor, Angiotensin, Type 2* ; RNA, Messenger ; Sulfatases

OBJECTIVE: To explore the expression of phospholipase Cgamma-2 (PLCgamma-2), lipoxygenase-12 (12-LOX) and arachidonic acid (AA) in laryngeal squamous cell carcinoma and to study the the relationship between lipid metabolism and laryngeal squamous cell carcinoma. METHOD: In 30 cases of carcinoma tissue and peritumoral laryngeal mucosa tissues (confirmed to be normal laryngeal tissues by pathology), immunohistochemical method (Streptavidin-peroxidase method, SP method) was used for the detection of expression of PLCgamma-2 and 12-LOX, and gas chromatography/mass spectrometry (GC/MS) for the content of the arachidonic acid in carcinoma tissue and peritumoral normal laryngeal mucosa tissues. RESULT: The positive rates of PLCgamma-2 and 12-LOX in carcinoma tissue were higher than in peritumoral normal laryngeal mucosa tissues with statistically significance differences (P < 0.05). The content of arachidonic acid was lower in carcinoma tissue than in peritumoral normal laryngeal mucosa tissues with statistically significance difference (P < 0.05). The positive expressions of PLCgamma-2 and 12-LOX were closely correlated to tnm stage, histological differentiation and lymph node metastasis (P < 0.05). The content of arachidonic acid had no significant correlations with tnm stage, histological differentiation and lymph node metastasis (P > 0.05). Both the expression of PLCgamma-2 and 12-LOX and the content of arachidonic acid had no statistically significant correlation with age (P > 0.05). CONCLUSION PLCgamma-2, AA and 12-LOX play important roles in laryngeal squamous cell carcinoma. It may be meaningful to the treatment of laryngeal carcinoma by suppressing this passway.
Aged ; Arachidonate 12-Lipoxygenase ; metabolism ; Arachidonic Acid ; metabolism ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Head and Neck Neoplasms ; metabolism ; pathology ; Humans ; Laryngeal Neoplasms ; metabolism ; pathology ; Male ; Middle Aged ; Neoplasm Staging ; Phospholipase C gamma ; metabolism ; Squamous Cell Carcinoma of Head and Neck

BACKGROUND: Extracellular sulfatases (Sulfs), sulfatase 1 (Sulf1) and sulfatase 2 (Sulf2), play a pivotal role in cell signaling by remodeling the 6-O-sulfation of heparan sulfate proteoglycans on the cell surface. The present study examined the effects of Sulfs on angiotensin II (Ang II)-induced hypertensive mediator expression and vascular smooth muscle cells (VSMCs) proliferation in spontaneously hypertensive rats (SHR).METHODS: Ang II receptors, 12-lipoxygenase (12-LO), and endothelin-1 (ET-1) messenger RNA (mRNA) expressions in SHR VSMCs were analyzed by real-time polymerase chain reaction and Western blotting. VSMCs proliferation was determined by [³ H]-thymidine incorporation.RESULTS: Basal Sulfs mRNAs expression and enzyme activity were elevated in SHR VSMCs. However, Sulfs had no effect on the basal or Ang II-induced 12-LO and ET-1 mRNA expression in SHR VSMCs. The inhibition of Ang II-induced 12-LO and ET-1 expression by blockade of the Ang II type 2 receptor (AT₂ R) pathway was not observed in Sulf1 siRNA-transfected SHR VSMCs. However, Sulf2 did not affect the action of AT₂ R inhibitor on Ang II-induced 12-LO and ET-1 expression in SHR VSMCs. The down-regulation of Sulf1 induced a reduction of AT₂ R mRNA expression in SHR VSMCs. In addition, the inhibition of Ang II-induced VSMCs proliferation by blockade of the AT₂ R pathway was mediated by Sulf1 in SHR VSMCs.CONCLUSION: These findings suggest that extracellular sulfatase Sulf1 plays a modulatory role in the AT₂ R pathway that leads to an Ang II-induced hypertensive effects in SHR VSMCs.
Angiotensin II ; Angiotensins ; Arachidonate 12-Lipoxygenase ; Blotting, Western ; Down-Regulation ; Endothelin-1 ; Heparan Sulfate Proteoglycans ; Hypertension ; Muscle, Smooth, Vascular ; Rats, Inbred SHR ; Real-Time Polymerase Chain Reaction ; Receptor, Angiotensin, Type 2 ; RNA, Messenger ; Sulfatases