SEPHS1: Its evolution, function and roles in development and diseases.

Selenophosphate synthetase (SEPHS) was originally discovered in prokaryotes as an enzyme that catalyzes selenophosphate synthesis using inorganic selenium and ATP as substrates. However, in contrast to prokaryotes, two paralogs, SEPHS1 and SEPHS2, occur in many eukaryotes. Prokaryotic SEPHS, also known as SelD, contains either cysteine (Cys) or selenocysteine (Sec) in the catalytic domain. In eukaryotes, only SEPHS2 carries out selenophosphate synthesis and contains Sec at the active site. However, SEPHS1 contains amino acids other than Sec or Cys at the catalytic position. Phylogenetic analysis of SEPHSs reveals that the ancestral SEPHS contains both selenophosphate synthesis and another unknown activity, and that SEPHS1 lost the selenophosphate synthesis activity. The three-dimensional structure of SEPHS1 suggests that its homodimer is unable to form selenophosphate, but retains ATPase activity to produce ADP and inorganic phosphate. The most prominent function of SEPHS1 is that it is implicated in the regulation of cellular redox homeostasis. Deficiency of SEPHS1 leads to the disturbance in the expression of genes involved in redox homeostasis. Different types of reactive oxygen species (ROS) are accumulated in response to SEPHS deficiency depending on cell or tissue types. The accumulation of ROS causes pleiotropic effects such as growth retardation, apoptosis, DNA damage, and embryonic lethality. SEPHS1 deficiency in mouse embryos affects retinoic signaling and other related signaling pathways depending on the embryonal stage until the embryo dies at E11.5. Dysregulated SEPHS1 is associated with the pathogenesis of various diseases including cancer, Crohn's disease, and osteoarthritis.

Selenophosphate synthetase 1 deficiency exacerbates osteoarthritis by dysregulating redox homeostasis.

Aging and mechanical overload are prominent risk factors for osteoarthritis (OA), which lead to an imbalance in redox homeostasis. The resulting state of oxidative stress drives the pathological transition of chondrocytes during OA development. However, the specific molecular pathways involved in disrupting chondrocyte redox homeostasis remain unclear. Here, we show that selenophosphate synthetase 1 (SEPHS1) expression is downregulated in human and mouse OA cartilage. SEPHS1 downregulation impairs the cellular capacity to synthesize a class of selenoproteins with oxidoreductase functions in chondrocytes, thereby elevating the level of reactive oxygen species (ROS) and facilitating chondrocyte senescence. Cartilage-specific Sephs1 knockout in adult mice causes aging-associated OA, and augments post-traumatic OA, which is rescued by supplementation of N-acetylcysteine (NAC). Selenium-deficient feeding and Sephs1 knockout have synergistic effects in exacerbating OA pathogenesis in mice. Therefore, we propose that SEPHS1 is an essential regulator of selenium metabolism and redox homeostasis, and its dysregulation governs the progression of OA.

The role of selenium metabolism and selenoproteins in cartilage homeostasis and arthropathies.

As an essential nutrient and trace element, selenium is required for living organisms and its beneficial roles in human health have been well recognized. The role of selenium is mainly played through selenoproteins synthesized by the selenium metabolic system. Selenoproteins have a wide range of cellular functions including regulation of selenium transport, thyroid hormones, immunity, and redox homeostasis. Selenium deficiency contributes to various diseases, such as cardiovascular disease, cancer, liver disease, and arthropathy-Kashin-Beck disease (KBD) and osteoarthritis (OA). A skeletal developmental disorder, KBD has been reported in low-selenium areas of China, North Korea, and the Siberian region of Russia, and can be alleviated by selenium supplementation. OA, the most common form of arthritis, is a degenerative disease caused by an imbalance in matrix metabolism and is characterized by cartilage destruction. Oxidative stress serves as a major cause of the initiation of OA pathogenesis. Selenium deficiency and dysregulation of selenoproteins are associated with impairments to redox homeostasis in cartilage. We review the recently explored roles of selenium metabolism and selenoproteins in cartilage with an emphasis on two arthropathies, KBD and OA. Moreover, we discuss the potential of therapeutic strategies targeting the biological functions of selenium and selenoproteins for OA treatment.

Pleiotropic roles of metallothioneins as regulators of chondrocyte apoptosis and catabolic and anabolic pathways during osteoarthritis pathogenesis.

OBJECTIVE: The zinc-ZIP8-MTF1 axis induces metallothionein (MT) expression and is a catabolic regulator of experimental osteoarthritis (OA) in mice. The main aim of the current study was to explore the roles and underlying molecular mechanisms of MTs in OA pathogenesis. METHODS: Experimental OA in mice was induced by destabilisation of the medial meniscus or intra-articular injection of adenovirus carrying a target gene (Ad-Zip8, Ad-Mtf1, Ad-Epas1, Ad-Nampt, Ad-Mt1 or Ad-Mt2) into wild type, Zip8fl/fl; Col2a1-Cre, Mtf1fl/fl; Col2a1-Cre and Mt1/Mt2 double knockout mice. Primary cultured mouse chondrocytes were infected with Ad-Mt1 or Ad-Mt2, and gene expression profiles analysed via microarray and reverse transcription-PCR. Proteins in human and mouse OA cartilage were identified via immunostaining. Chondrocyte apoptosis in OA cartilage was determined using terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labelling (TUNEL). RESULTS: MTs were highly expressed in human and mouse OA cartilage. Hypoxia-inducible factor 2α, nicotinamide phosphoribosyltransferase and several proinflammatory cytokine pathways, as well as the zinc-ZIP8-MTF1 axis were identified as upstream regulators of MT expression. Genetic deletion of Mt1 and Mt2 enhanced cartilage destruction through increasing chondrocyte apoptosis. Unexpectedly, aberrant overexpression of MT2, but not MT1, induced upregulation of matrix-degrading enzymes and downregulation of matrix molecules through nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) activation, ultimately leading to OA. CONCLUSIONS: MTs play an antiapoptotic role in post-traumatic OA. However, aberrant and chronic upregulation of MT2 triggers an imbalance between chondrocyte anabolism and catabolism, consequently accelerating OA development. Our findings collectively highlight pleiotropic roles of MTs as regulators of chondrocyte apoptosis as well as catabolic and anabolic pathways during OA pathogenesis.

Three-dimensional analysis of maxillary anatomic landmarks for greater palatine nerve block anesthesia.

Greater palatine nerve block anesthesia (GPNBA) is a local anesthetic procedure used for maxillary and nasal treatment. Investigation of the three-dimensional anatomic location of the greater palatine foramen (GPF) is important for successful local anesthesia. The study aim was to provide standards for anatomic structures in the oral cavity that can be easily referred to in GPNBA. Maxillary computed tomography data were obtained from patients between 8 and 16 years of age whose maxillary incisors and first molars had already erupted (the growth group, n = 103); changes in the maxilla were observed over time in this group. Reference values for GPNBA in adults were measured in 107 patients older than 18 years. Maxillary computed tomography images were reconstructed three-dimensionally. Regression analysis demonstrates that all maxillary measurements in the growth group except for the distance from the posterior nasal spine to the GPF in the coronal plane correlated significantly with age. In adults, the mean perpendicular distance from the interdental alveolar bone between the left and right central incisors (1alvB) to the GPF in the coronal plane was 46.16 mm, and the mean distance from 1alvB to the GPF was 51.05 mm. The mean distance from the maxillary central incisor to the GPF was 57.58 mm. The mean angle between the line from the maxillary central incisor to each GPF and the sagittal plane was 16.49 degrees. The mean perpendicular distance from the anterior nasal spine to the GPF in the coronal plane was 43.49 mm, whereas the mean perpendicular distance from the GPF to the bone plane was 12.67 mm, and the mean perpendicular distance from the GPF to the occlusal plane was 22.13 mm. These measurements can be used to find the height of the GPF. In adults, the measured perpendicular distance from the incisive foramen to the GPF in the coronal plane was 32.04 mm, and the perpendicular distance from the median of the line that connects both of the contact points between the maxillary tuberosity and the pterygoid plate to the GPF in the coronal plane was 5.23 mm. Three-dimensional reference values relative to the anatomic structures in the oral cavity may increase the success rate of GPNBA and reduce complications. Although the maxillary growth pattern was analyzed, a limitation of this study is that maxillary anatomic measurements were not analyzed with regard to race or ethnicity.

Antioxidant effects of equol on bovine aortic endothelial cells.

This study is to examine the effects of equol on the H(2)O(2)-induced death of bovine aortic endothelial cells (bAECs) and the mechanism of its protective effects. MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] assay showed that in the control group, cell survival rate decreased significantly, each in proportion to the duration of the H(2)O(2) stimulation (P<0.05), but, in the equol-pretreated group, such decrease was not statistically significant. After Hoechst 33342 staining, in the equol-pretreated group the number of cells with apoptotic morphology decreased significantly. Equol pretreatment effectively inhibited the H(2)O(2)-induced cell death by the reduction of intracellular ROS production (P<0.05). Incubation of bAECs with equol increased the expression of phospho-p38 MAPK and Bcl-2 after the H(2)O(2) exposure compared with their expression without the equol pretreatment. Furthermore, SB203580 inhibited phospho-p38 MAPK expression and increased apoptotic cell death. This study proves equol has a significant antioxidant effect on the bAECs that were exposed to H(2)O(2).

Transvaginal radiofrequency thermal ablation: a day-care approach to symptomatic uterine myomas.

BACKGROUND: In patients with myoma, the traditional surgical treatment of choice is myomectomy for women who wish to retain their uterus. However, myomectomy must be performed under general anaesthesia, and the patient requires a long time to recover. AIMS: In the present study, we report our experience with a group of patients who underwent transvaginal radiofrequency (RF) thermal ablation of uterine myomas, with emphasis on the safety and efficacy of this procedure. METHODS: Premenopausal women with symptomatic uterine myoma or recently growing myoma were included in this study. The pre- and postoperative myoma volumes were measured by 3D ultrasonography. The impact of the symptoms on health-related quality of life (HRQL) was assessed using the Uterine Fibroids Symptom and Quality of Life questionnaire. RESULTS: The mean initial size of the dominant myoma was 5.3 cm (standard deviation +/- 1.58). The reoperation rate was 4.3%. The final reduction rate of the volume of the dominant fibroid was 73%. The symptom scores and HRQL scores showed great improvement after 18 months of myolysis. CONCLUSIONS: The results of this study suggest that RF ablation may represent a safe, well-tolerated, and effective day-care alternative to conventional surgery for the treatment of uterine myomas.

Short-term effects of magnetic sacral dermatome stimulation for idiopathic slow transit constipation: sham-controlled, cross-over pilot study.

BACKGROUND AND AIM: An increase in recto-sigmoid colon activity through electrical stimulation of the sacral dermatomes has previously been reported. It has not been evaluated whether or not sacral dermatome stimulation has beneficial effects on constipation symptoms and anorectal function in constipated patients. Our aim was to evaluate short-term effects of magnetic stimulation of the sacral dermatomes on constipation symptoms and anorectal function in patients with idiopathic slow transit constipation. METHOD: Fourteen patients with idiopathic slow transit constipation were enrolled. Constipation symptoms, stool form and anorectal function were assessed before treatment, and at 3 and 6 weeks of treatment. Six-week treatment consisted of either a 3-week period of sham treatment or a 3-week period of magnetic stimulation of the S2-S3 dermatomes, which was performed in a randomized cross-over design. RESULTS: During the stimulation period, the frequency score of spontaneous bowel movements decreased in eight of the 14 patients (2.9 [2-3]vs 1.4 [0-2]), whose threshold volumes for urge to defecate and maximum tolerable volumes were significantly greater than those of the non-responders, and significantly decreased at the end of treatment. The degree of straining on defecation also significantly decreased in the responders. Responders had shorter right colonic transit time and longer left colonic transit time compared to the non-responders. Sham treatment did not affect constipation symptoms, stool form and rectal sensation. CONCLUSION: Sacral dermatome stimulation may offer potential for therapeutic benefit for a subset of patients with idiopathic slow transit constipation, particularly constipated patients with rectal hyposensation or hindgut dysfunction.

Novel antioxidant ameliorates the fibrosis and inflammation of cerulein-induced chronic pancreatitis in a mouse model.

BACKGROUND/AIM: Oxygen free radicals (OFRs) mediate an important step in the initiation of experimental acute pancreatitis and several clinical findings suggested the possible contribution of OFRs to the pathogenesis of pancreatic fibrosis. So far, there are no studies which reporting potential role of OFRs in development of chronic pancreatitis with the prevention with antioxidants. This study was aimed to establish the mice model of chronic fibrosing pancreatitis and to prove the involvement of OFRs in chronic pancreatitis with fibrosis. METHODS: Repeated intraperitoneal cerulein injection was performed to induce chronic pancreatitis in mice. Histological changes in the pancreas were examined, and markers for oxidative stress were measured in the pancreatic tissue and serum of the mice. DA-9601, a phytochemical possessing anti-inflammatory and antioxidative action, was given together with cerulein to the mice. RESULTS: Repeated intraperitoneal injection of cerulein provoked significant severity of chronic fibrosing pancreatitis after 5 weeks. After treatment of DA-9601, the extents of pancreatic fibrosis were statistically significantly decreased in accordance with lessened pancreatic inflammations. The NF-kappaB binding activities were increased in chronic pancreatitis, which were significantly attenuated after DA-9601 treatment. The levels of myeloperoxidase and iNOS activities were also significantly decreased in DA-9601-treated group compared to the pancreatitis only group. Cytoprotective proteins such as heat shock protein-70 (HSP) and metallothionein were significantly increased in the DA-9601-treated group. DA-9601 decreased the expressions of alpha-SMA and type I collagen in cultured pancreatic stellate cells. CONCLUSIONS: Oxidative stress was principally involved in the pathogenesis of chronic pancreatitis with fibrosis.

Amomum xanthoides extract prevents cytokine-induced cell death of RINm5F cells through the inhibition of nitric oxide formation.

We previously showed that Amomum xanthoides extract prevented alloxan-induced diabetes through the suppression of NF-kappaB activation. In this study, the preventive effects of A. xanthoides extract on cytokine-induced beta-cell destruction were examined. Cytokines produced by immune cells infiltrating pancreatic islets are important mediators of beta-cell destruction in insulin-dependent diabetes mellitus. A. xanthoides extract completely protected interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma)-mediated cytotoxicity in rat insulinoma cell line (RINm5F). Incubation with A. xanthoides extract resulted in a significant reduction in IL-1beta and IFN-gamma-induced nitric oxide (NO) production, a finding that correlated well with reduced levels of the inducible form of NO synthase (iNOS) mRNA and protein. The molecular mechanism by which A. xanthoides extract inhibited iNOS gene expression appeared to involve the inhibition of NF-kappaB activation. Our results revealed the possible therapeutic value of A. xanthoides extract for the prevention of diabetes mellitus progression.

[Suppressive effects of antioxidant DA-9601 on hepatic fibrosis in rats].

BACKGROUND/AIMS: Oxidative stress is one of the important underlying mechanisms of hepatic fibrosis. DA-9601, the ethanol extracts of Artemisia asiatica, has been reported to possess strong antioxidative and cytoprotective actions. We tried to evaluate whether antioxidant can ameliorate dimethylnitrosamine (DMN)-induced hepatic fibrosis. METHODS: Rat hepatic fibrosis was induced by intraperitoneal administrations of 10 mg DMN six times. Additionally, rats of one group were started daily with DA-9601 30 mg/kg containing diets and another group was fed a pellet diet containing DA-9601 100 mg/kg. The immunohistochemical studies for collagen, alpha-smooth muscle actin (alpha-SMA), and fibronectin, the measurements of hepatic malondialdehyde (MDA) and collagens, and the changes of liver function profiles were performed. Hepatic stellate cells (HSC) were isolated and in vitro effects of DA-9601 on HSC activations were measured. RESULTS: DA-9601 significantly attenuated the loss of body weights (p<0.05), the reduction of liver wet weights (p<0.05), and the elevation of liver enzymes provoked by DMN administrations. DMN injections caused the severe fibrosis of portal tract, hepatic inflammation, and significant oxidative damages, but DA-9601 treatment significantly reduced the mean scores of hepatic fibrosis, the amounts of hepatic collagens, and hepatic MDA levels. The prominent decreases in the expressions of collagens type I & III, alpha-SMA, and fibronectin or hepatic inflammations were observed in DA-9601-treated groups dose-dependently and similar efficacy was also proven in in vitro HSC experiment. CONCLUSIONS: DA-9601 effectively protected rat liver tissues against the DMN-induced hepatic fibrosis. Antioxidant could be considered as a supplementary therapeutic for alleviating the hepatic fibrosis.