Primary systemic carnitine deficiency (SCD; OMIM 212140) is an autosomal recessive disorder characterized by progressive cardiomyopathy, skeletal myopathy, hypoglycaemia and hyperammonaemia. SCD has also been linked to sudden infant death syndrome. Membrane-physiological studies have suggested a defect of the carnitine transport system in the plasma membrane in SCD patients and in the mouse model, juvenile visceral steatosis. Although the responsible loci have been mapped in both human and mouse, the underlying gene has not yet been identified. Recently, we cloned and analysed the function of a novel transporter protein termed OCTN2. Our observation that OCTN2 has the ability to transport carnitine in a sodium-dependent manner prompted us to search for mutations in the gene encoding OCTN2, SLC22A5. Initially, we analysed the mouse gene and found a missense mutation in Slc22a5 in jvs mice. Biochemical analysis revealed that this mutation abrogates carnitine transport. Subsequent analysis of the human gene identified four mutations in three SCD pedigrees. Affected individuals in one family were homozygous for the deletion of a 113-bp region containing the start codon. In the second pedigree, the affected individual was shown to be a compound heterozygote for two mutations that cause a frameshift and a premature stop codon, respectively. In an affected individual belonging to a third family, we found a homozygous splice-site mutation also resulting in a premature stop codon. These mutations provide the first evidence that loss of OCTN2 function causes SCD.

Serum free-carnitine levels were determined in 973 unrelated white collar workers in Akita, Japan. Fourteen of these participants consistently had serum free-carnitine levels below the fifth percentile (28 microM for females and 38 microM for males). The OCTN2 (organic cation transporter) gene was sequenced for these 14 subjects, for 22 subjects whose carnitine levels were below the fifth percentile in the first screening but were normal in the second measurement and in 69 individuals with normal carnitine levels for two separate measurements. Polymorphic sequences defined three major haplotypes with equal frequency. Mutations were identified in nine subjects with low carnitine levels: Trp132X (three individuals), Ser467Cys (four), Trp283Cys (one) and Met179Leu (one). In vitro expression studies in HEK cells indicated that Ser467Cys and Trp283Cys, but not Met179Leu, significantly reduced L-carnitine uptake relative to the normal control. Trp132X and Ser467Cys were associated with specific haplotypes, suggesting a founder effect. A conservative estimate of the overall prevalence of heterozygotes was 1.01% in the Akita prefecture, Japan, giving an estimated incidence of primary systemic carnitine deficiency (MIM 212140) as 1 in 40 000 births. An echocardiographic study of the families of patients with primary carnitine deficiency revealed that the heterozygotes for OCTN2 mutations were predisposed to late onset benign cardiac hypertrophy (odds ratio 15.1, 95% CI 1.39-164) compared with the wild-types. Sequencing of DNA isolated from three deceased siblings (1.5-8 years) in two families retrospectively confirmed that all three deceased subjects were homozygous for the OCTN2 mutations.

foci (ACF) and/or intestinal polyps has been suggested. In contrast, EP 3 appears to have no influence on the early stages of colon carcinogenesis. In the present study, we examined expression of PGE 2 receptor subtypes EP 1 , EP 2 , EP 3 , and EP 4 in normal colon mucosa and colon cancers, and assessed the contribution of EP 3 to colon cancer development. Methods: mRNA expression of PGE 2 receptor subtypes EP 1 , EP 2 , EP 3 , and EP 4 in normal colon mucosa and colon cancers in azoxymethane (AOM) treated mice and rats, and in humans, were examined by reverse transcription-polymerase chain reaction (RT-PCR), quantitative real time RT-PCR, and immunohistochemical analyses. Evaluation of the role of EP 3 was performed by intraperitoneal injection of AOM, using EP 3 receptor knockout mice. Effects of EP 3 receptor activation on cell growth of human colon cancer cell lines were examined using ONO-AE-248, an EP 3 selective agonist. Moreover, EP 3 expression in colon cancer cell lines was analysed with or without 5-aza-29-deoxycytidine (5-aza-dC) treatment. Results: Expression levels of EP 1 and EP 2 mRNA were increased in cancer tissues. EP 4 mRNA was constantly expressed in normal mucosa and cancers. In contrast, expression of EP 3 mRNA was markedly decreased in colon cancer tissues, being 5% in mice, 9% in rats, and 28% in humans compared with normal colon mucosa, analysed by quantitative real time RT-PCR. Immunohistochemical staining demonstrated the rat EP 3 receptor protein to be expressed in epithelial cells of normal mucosa and some parts of small carcinomas but hardly detectable in large carcinomas of the colon. Colon cancer development induced by AOM in EP 3 receptor knockout mice was enhanced compared with wild-type mice, with a higher incidence of colon tumours (78% v 57%) and mean number of tumours per mouse (2.17 (0.51) v 0.75 (0.15); p,0.05). Expression of EP 3 mRNA was detected in only one of 11 human colon cancer cell lines tested. Treatment with 5 mM of an EP 3 selective agonist, ONO-AE-248, resulted in a 30% decrease in viable cell numbers in the HCA-7 human colon cancer cell line in which EP 3 was expressed. Treatment with 5-aza-dC restored EP 3 expression in CACO-2, CW-2, and DLD-1 cells but not in WiDr cells, suggesting involvement of hypermethylation in the downregulation of EP 3 to some extent. Conclusion: The PGE 2 receptor subtype EP 3 plays an important role in suppression of cell growth and its downregulation enhances colon carcinogenesis at a later stage. Hypermethylation of the EP 3 receptor gene could occur and may contribute towards downregulating EP 3 expression to some extent in colon cancers.

Endometriosis is considered to be a polygenic disease with a complex, multifactorial aetiology that affects about 10% of women in the reproductive age. Women with endometriosis have symptoms that include chronic pelvic pain, dysmenorrhoea and dyspareunia, significantly reducing their quality of life. Endometriosis is also the primary cause of infertility in women, with the prevalence rate ranging from 20% to 50%. The high prevalence and severe outcomes of this disease have made it a major public health concern in modern society. Currently, the mechanism(s) responsible for the initiation and promotion of this disease remains obscure. In this review, we focus on the expression, regulation and action of prostaglandins in the cellular and molecular mechanisms that contribute to the development and/or maintenance of endometriosis.

Decreased phagocytotic ability of macrophages has been reported to be associated with the severity of endometriosis, although the underlying mechanism remains uncharacterized. Expression and secretion of matrix metalloproteinase (MMP)-9 by macrophages is a means to degrade the extracellular matrix of cells that are designated for phagocytosis. Here, we describe the regulation of MMP-9 expression and activity in peritoneal macrophages of women with endometriosis. Results demonstrated that peritoneal macrophages isolated from women with endometriosis have decreased levels of protein and enzyme activity of MMP-9. Treatment of macrophages with peritoneal fluid obtained from patients with severe endometriosis inhibited MMP-9 expression and gelatinase activity. Further investigation identified prostaglandin (PG) E 2 as the major factor in the peritoneal fluid that inhibited MMP-9 activity. The inhibitory effect of PGE 2 was mediated via the EP2/EP4-dependent PKA pathway. Furthermore, expression of tissue inhibitor of metalloproteinase-1, tissue inhibitor of metalloproteinase-2, and RECK in macrophages was not affected by treatment with PGE 2 , indicating the effect of PGE 2 on suppressing MMP-9 activity was not mediated by up-regulation of its inhibitor. Our results suggest that decreased phagocytotic capability of peritoneal macrophage in patients with endometriosis may be caused by PGE 2 -mediated decreases in MMP-9 expression. Endometriosis is a common gynecological disorder with a complex, multifactorial etiology that causes chronic pelvic pain, dysmenorrhea, and even infertility. The prevalence of this disease is ϳ10 to 15% among women of reproductive age. The underlying pathophysiological mechanism is still enigmatic. Although retrograde menstruation has been suggested to be the crucial constituent in the development of endometriosis, 1 factors allowing the implantation and propagation of endometriotic lesions are primarily unclear. Aberrant production of steroids by ectopic endometriotic lesions and alteration/ dysfunction of the immune system may lead to the development of endometriosis.2-5 During the development of endometriosis, immune cells are recruited into the peritoneal cavity. Among these immune cells, macrophages are the dominant cell type in the peritoneal cavity and are involved in phagocytosis and inflammation, especially in cleaning the retrograded endometrial debris.6,7 Peritoneal macrophages isolated from patients with endometriosis were found to have phenotypic and functional alterations leading to poor phagocytotic capacity, which is highly associated with severity of endometriosis. 4,8 Nevertheless, the mechanism of suppressed phagocytotic capability of macrophages in endometriosis is poorly understood.Matrix metalloproteinases (MMPs), also called matrixins, are proteinases that participate in extracellular matrix degradation.9 Based on substrate specificity, sequence similarity, and domain organization, vertebrate MMPs can be divided into six groups such as collagenases, gelatinases, stromel...