Cardiac overexpression of perilipin 2 induces atrial steatosis, connexin 43 remodeling, and atrial fibrillation in aged mice

Atrial fibrillation (AF) is prevalent in patients with obesity and diabetes, and such patients often exhibit cardiac steatosis. Since the role of cardiac steatosis per se in the induction of AF has not been elucidated, the present study was designed to explore the relation between cardiac steatosis and AF. Transgenic (Tg) mice with cardiac-specific overexpression of perilipin 2 (PLIN2) were housed in the laboratory for more than 12 mo before the study. Electron microscopy of the atria of PLIN2-Tg mice showed accumulation of small lipid droplets around mitochondrial chains, and five- to ninefold greater atrial triacylglycerol (TAG) content compared with wild-type (WT) mice. Electrocardiography showed significantly longer RR intervals in PLIN2-Tg mice than in WT mice. Transesophageal electrical burst pacing resulted in significantly higher prevalence of sustained (>5 min) AF (69%) in PLIN2-Tg mice than in WT mice (24%), although it was comparable in younger (4-mo-old) mice. Connexin 43 (Cx43), a gap junction protein, was localized at the intercalated disks in WT atria but was heterogeneously distributed on the lateral side of cardiomyocytes in PLIN2-Tg atria. Langendorff-perfused hearts using the optical mapping technique showed slower and heterogeneous impulse propagation in PLIN2-Tg atria compared with WT atria. Cardiac overexpression of hormone-sensitive lipase in PLIN2-Tg mice resulted in atrial TAG depletion and amelioration of AF susceptibility. The results suggest that PLIN2-induced steatosis is associated with Cx43 remodeling, impaired conduction propagation, and higher incidence of AF in aged mice. Therapies targeting cardiac steatosis could be potentially beneficial against AF in patients with obesity or diabetes.

Pycnogenol protects against diet-induced hepatic steatosis in apolipoprotein-E-deficient mice

Pycnogenol^R (PYC), a combination of active flavonoids derived from French maritime pine bark, is a natural antioxidant that has various pharmacological activities. Here, we investigated the beneficial effect of PYC on diet-induced hepatic steatosis. Apolipoprotein E (ApoE)-deficient male mice were administered PYC at oral doses of 30 or 100 mg·kg^-1·day^-1 for 2 wk in advance and were then fed a high-cholesterol and -fat diet (HCD) for 8 wk. Biochemical, immunohistochemical, and gene expression analyses were conducted to explore the effect of PYC on lipid metabolism in ApoE-deficient mice on a HCD. Short-term treatment with HCD in ApoE-deficient mice induced hepatic injuries, such as lipid metabolism disorder and hepatic histopathological changes. We found that PYC reduced body weight and the increase of serum lipids that had been caused by HCD. Supplementation of PYC significantly reduced lipid deposition in the liver, as shown by the lowered hepatic lipid content and histopathological lesions. We subsequently detected genes related to lipid metabolism and inflammatory cytokines. The study showed that PYC markedly suppressed the expression of genes related to hepatic lipogenesis, fatty acid uptake, and lipid storage while increasing the lipolytic gene, which thus reduced hepatic lipid content. Furthermore, PYC mainly reduced the expression of inflammatory cytokines and the infiltration of inflammatory cells, which were resistant to the development of hepatic steatosis. These results demonstrate that PYC protects against the occurrence and development of hepatic steatosis and may provide a new prophylactic approach for nonalcoholic fatty liver disease (NAFLD).

Pycnogenol® Induces Browning of White Adipose Tissue through the PKA Signaling Pathway in Apolipoprotein E-Deficient Mice

Beige adipocytes in white adipose tissue (WAT) have received considerable recognition because of their potential protective effect against obesity. Pycnogenol (PYC), extracted from French maritime pine bark, has anti-inflammatory and antioxidant properties and can improve lipid profiles. However, the effect of PYC on obesity has never been explored. In this study, we investigated the effects of PYC on obesity and WAT browning in apolipoprotein E- (ApoE-) deficient mice. The results showed that PYC treatment clearly reversed body weight and the mass of eWAT gain resulting from a high-cholesterol and high-fat diet (HCD), but no difference in food intake. The morphology results showed that the size of the adipocytes in the PYC-treated mice was obviously smaller than that in the HCD-fed mice. Next, we found that PYC upregulated the expression of genes related to lipolysis (ATGL and HSL), while it decreased the mRNA level of PLIN1. PYC significantly increased the expression of UCP1 and other genes related to beige adipogenesis. Additionally, PYC increased the expression of proteins related to the protein kinase A (PKA) signaling pathway. The findings suggested that PYC decreased obesity by promoting lipolysis and WAT browning. Thus, PYC may be a novel therapeutic target for obesity.

Cardiac overexpression of perilipin 2 induces dynamic steatosis: prevention by hormone-sensitive lipase

Cardiac intracellular lipid accumulation (steatosis) is a pathophysiological phenomenon observed in starvation and diabetes mellitus. Perilipin 2 (PLIN2) is a lipid droplet (LD)-associated protein expressed in nonadipose tissues, including the heart. To explore the pathophysiological function of myocardial PLIN2, we generated transgenic (Tg) mice by cardiac-specific overexpression of PLIN2. Tg hearts showed accumulation of numerous small LDs associated with mitochondrial chains and high cardiac triacylglycerol (TAG) content [8-fold greater than wild-type (WT) mice]. Despite massive steatosis, cardiac uptake of glucose, fatty acids and VLDL, systolic function, and expression of metabolic genes were comparable in the two genotypes, and no morphological changes were observed by electron microscopy in the Tg hearts. Twenty-four hours of fasting markedly reduced steatosis in Tg hearts, whereas WT mice showed accumulation of LDs. Although activity of adipose triglyceride lipase in heart homogenate was comparable between WT and Tg mice, activity of hormone-sensitive lipase (HSL) was 40-50% less in Tg than WT mice under both feeding and fasting conditions, suggesting interference of PLIN2 with HSL. Mice generated through crossing of PLIN2-Tg mice and HSL-Tg mice showed cardiac-specific HSL overexpression and complete lack of steatosis. The results suggest that cardiac PLIN2 plays an important pathophysiological role in the development of dynamic steatosis and that the latter was prevented by upregulation of intracellular lipases, including HSL.

Rupture of small cystic pancreatic neuroendocrine tumor with many microtumors

Pancreatic neuroendocrine tumors (pNETs) are particularly rare. The various forms of PNETs, such as cystic degeneration, make differentiation from other similar pancreatic lesions difficult. We can detect small lesions by endoscopic ultrasound (EUS) and obtain preoperative pathological diagnosis by EUS-guided fine needle aspiration (FNA). We describe, here, an interesting case of pNET in a 42-year-old woman with no family history. Computed tomography and magnetic resonance imaging revealed an 18 mm × 17 mm cystic lesion with a nodule in the pancreatic tail. Two microtumors about 7 mm in diameter in the pancreatic body detected only by EUS, cystic rim and nodules all showed similar enhancement on contrast-harmonic EUS. Preoperative EUS-FNA of the microtumor was performed, diagnosing multiple pNETs. Macroscopic examination of the resected pancreatic body and tail showed that the cystic lesion had morphologically changed to a 13-mm main nodule, and 11 new microtumors (diameter 1-3 mm). Microscopically, all microtumors represented pNETs. From the findings of a broken peripheral rim on the main lesion with fibrosis, rupture of the cystic pNET was suspected. Postoperatively, pituitary adenoma and parathyroid adenoma were detected. The final diagnosis was multiple grade 1 pNETs with multiple endocrine neoplasia type 1. To the best of our knowledge, no case of spontaneous rupture of a cystic pNET has previously been reported in the English literature. Therefore, this case of very rare pNET with various morphological changes is reported.

Pycnogenol Attenuates the Release of Proinflammatory Cytokines and Expression of Perilipin 2 in Lipopolysaccharide-Stimulated Microglia in Part via Inhibition of NF-κB and AP-1 Activation

Over activation of microglia results in the production of proinflammatory agents that have been implicated in various brain diseases. Pycnogenol is a patented extract from French maritime pine bark (Pinus pinaster Aiton) with strong antioxidant and anti-inflammatory potency. The present study investigated whether pycnogenol may be associated with the production of proinflammatory mediators in lipopolysaccharide-stimulated BV2 (mouse-derived) microglia. It was found that pycnogenol treatment was dose-dependently associated with significantly less release of nitricoxide (NO), TNF-α, IL-6 and IL-1β, and lower levels of intercellular adhesion molecule1 (ICAM-1) and perilipin 2 (PLIN2). Furthermore, this effect was replicated in primary brain microglia. Levels of inducible NO synthase mRNA and protein were attenuated, whereas there was no change in the production of the anti-inflammatory cytokine IL-10. Further evidence indicated that pycnogenol treatment led to the suppression of NF-κB activation through inhibition of p65 translocation into the nucleus and inhibited DNA binding of AP-1, suggesting that these proinflammatory factors are associated with NF-κB and AP-1. We conclude that pycnogenol exerts anti-inflammatory effects through inhibition of the NF-κB and AP-1pathway, and may be useful as a therapeutic agent in the prevention of diseases caused by over activation of microglia.

Primary Sjögren's syndrome complicated by sarcoidosis and psoriasis vulgaris

Abstract Primary Sjögren's syndrome (SS), sarcoidosis (SA), and psoriasis vulgaris (PV) are all chronic diseases of unknown etiology. Recent studies suggest that activated T cells play a central role in their pathogenesis. We describe a case of a Japanese woman with primary SS complicated by SA and PV. To our knowledge, this is the first case in which these three diseases coexist. Although these three disorders may have a common immunopathogenic mechanism, the extreme rarity of their coexistence suggests that distinct etiological mechanisms are also involved and appear to play an important role in triggering and developing each disease.

Molecular mechanism of intracellular lipid accumulation: Suppressive effect of PycnogenolR in liver cells

Cells are physiologically ready to accumulate lipids such as triacylglycerides in the cytoplasm. Five classes of perilipin (PLIN) family proteins are known to be involved in the process of intracellular lipid accumulation. PLIN2 is expressed ubiquitously including adipocytes, hepatocytes and macrophages. Over-expression of PLIN2 is demonstrated in the lesions of fatty liver diseases and atherosclerosis. Suppression of PLIN2 expression prevents from developing these pathological conditions in animal models, suggesting that PLIN2 could be a therapeutic target molecule for excessive intracellular lipid accumulation which leads to various metabolic derangements. The PLIN2 gene promoter has two important cis-acting elements in close proximity:AP-1 element which mediates inflammatory signals and PPRE which mediates free fatty acid effect. In NMuLi mouse liver cells, FFA such as oleic acid requires both functional AP-1 and PPRE simultaneously to stimulate the promoter activity, indicating the presence of intimate interaction of inflammatory and metabolic signals on this gene. PycnogenolR, French maritime pine bark extracts, suppressed the oleic acid-induced PLIN2 expression and lipid accumulation in NMuLi cells. We found that PycnogenolR did not suppress the PLIN2 promoter activity or AP-1 binding to DNA. Instead, PycnogenolR facilitates the PLIN2 mRNA degradation, leading to suppression of lipid accumulation. This effect seems to be independent of antioxidant effect of PycnogenolR. We raise the idea that PLIN2 is a putative target molecule for prevention of pathological condition induced by excessive lipid accumulation, and this class of natural compounds could be putative therapeutic modalities.Key words: PycnogenolR, lipid droplet, perilipin, fatty liver disease

High glucose, insulin and free fatty acid concentrations synergistically enhance perilipin 3 expression and lipid accumulation in macrophages

OBJECTIVE

Perilipin (PLIN) 3, an intracellular lipid droplet (LD)-associated protein, is implicated in foam cell formation. Since metabolic derangements found in metabolic syndrome, such as high serum levels of glucose, insulin and free fatty acids (FFAs), are major risk factors promoting atherosclerosis, we investigated whether PLIN3 expression is affected by glucose, insulin and oleic acid (OA) using RAW264.7 cells.

METHODS

Real-time PCR and Western blotting were performed to detect PLIN3 or PLIN2 expression. Oil-red O staining and Lipid Analysis were employed to measure cellular content of triacylglycerides (TAG) and cholesterol.

RESULTS

PLIN3 mRNA was stimulated by high glucose or insulin concentrations individually, but not by OA. A combination of any two factors did not enhance PLIN3 expression any more than that evoked by glucose alone at 24h. Interestingly, however, simultaneous addition of all three factors synergistically enhanced the PLIN3 expression. This synergistic effect was not apparent for PLIN2 mRNA expression. Inhibitors of Src family tyrosine kinase and/or phosphatidylinositol 3-kinase, both of which are activated by insulin and FFA signaling, partially suppressed PLIN3 expression induced by the combination of the three factors. While simultaneous addition of glucose, insulin and OA remarkably increased the cellular content of TAG and cholesterol, knocking-down of PLIN3 predominantly reduced TAG content.

CONCLUSIONS

These results indicate that PLIN3 expression is synergistically stimulated by high glucose, insulin and FFA concentrations, in parallel with TAG accumulation in macrophages. This finding raises new evidence of PLIN3 involvement in conversion of macrophages into foam cells.

Oral low-dose tacrolimus therapy for refractory hemophagocytic syndrome associated with systemic lupus erythematosus

Hemophagocytic syndrome (HPS) is an unusual disorder associated with systemic lupus erythematosus (SLE). A 64-year-old woman was admitted because of fever and urticarial vasculitis. Laboratory data revealed pancytopenia and immunological abnormalities, suggesting elevated disease activity. Prednisolone monotherapy failed to improve the pancytopenia despite the amelioration of other clinical findings. Because her condition was suggestive of HPS, tacrolimus at 2-3 mg/day was added to the prednisolone regimen. Eventually, the pancytopenia improved and prednisolone could be effectively tapered. Tacrolimus could be an additional or alternative modality for treating refractory HPS.

A Toll-like receptor 9-mediated pathway stimulates perilipin 3 (TIP47) expression and induces lipid accumulation in macrophages

Excessive accumulation of lipids in macrophages results in formation of foam cells and is a hallmark of atherosclerosis. The PAT family of proteins has been implicated in this process, but details of their involvement in foam cell formation have not been fully elucidated. One of dominant members of the PAT proteins, perilipin 3 (TIP47), is likely to be involved in such a regulatory mechanism. In this study, we demonstrated that the Toll-like receptor 9 (TLR9)-mediated pathway stimulates perilipin 3 expression and accumulation of lipids, especially triglycerides, in macrophages. Oligodeoxynucleotide (ODN) 1826, a ligand of TLR9, significantly enhanced perilipin 3 expression in RAW264.7 cells, and chloroquine, a TLR9 inhibitor, almost completely inhibited ODN1826-induced perilipin 3 expression. The inhibitors of c-jun NH2-terminal kinase and PI 3-kinase suppressed the level of perilipin 3 mRNA induced by ODN1826. ODN1826 induced the expression of IL-1α and IFNβ, both of which increased perilipin 3 expression. Antibodies against these cytokines suppressed the ODN1826-induced perilipin 3 mRNA levels. These results suggest that the expression of perilipin 3 in macrophages is in part regulated through the TLR9-mediated mechanism. Furthermore, ODN1826 increased intracellular lipid accumulation in the presence of oxLDL, which was reduced by perilipin 3 siRNA. Perilipin 3 expression was not stimulated by oxLDL. Depletion of perilipin 3 by siRNA specifically reduced triglyceride content in the cells but not cholesterol content, indicating that perilipin 3 is involved mainly in triglyceride accumulation. In conclusion, the TLR9-mediated pathway facilitates foam cell formation in part through increased expression of perilipin 3.

Oleic acid-induced ADRP expression requires both AP-1 and PPAR response elements, and is reduced by Pycnogenol through mRNA degradation in NMuLi liver cells

Fatty acids stimulate lipid accumulation in parallel with increased expression of adipose differentiation-related protein (ADRP) in liver cells. Although it is generally considered that the fatty acid effect on ADRP expression is mediated by peroxisome proliferator-activated receptors (PPARs), we identified here an additional molecular mechanism using the NMuLi mouse liver nonparenchymal cell line, which expresses PPARgamma and delta but not alpha. Oleic acid (OA) and specific ligands for PPARgamma and -delta stimulated ADRP expression as well as the -2,090-bp ADRP promoter activity which encompasses the PPAR response element (PPRE) adjacent to an Ets/activator protein (AP)-1 site. When the AP-1 site was mutated, OA failed to stimulate the activity despite the presence of the PPRE, whereas ligands for PPARgamma and -delta did stimulate it and so did a PPARalpha ligand under the coexpression of PPARalpha. DNA binding of AP-1 was stimulated by OA but not by PPAR ligands. Because we previously demonstrated that Pycnogenol (PYC), a French maritime pine bark extract, suppressed ADRP expression in macrophages partly by suppression of AP-1 activity, we tested the effect of PYC on NMuLi cells. PYC reduced the OA-induced ADRP expression along with suppression of lipid droplet formation. However, PYC neither suppressed the OA-stimulated ADRP promoter activity nor DNA binding of AP-1 but, instead, reduced the ADRP mRNA half-life. All these results indicate that the effect of OA on ADRP expression requires AP-1 as well as PPRE, and PYC suppresses the ADRP expression in part by facilitating mRNA degradation. PYC, a widely used dietary supplement, could be beneficial for the prevention of excessive lipid accumulation such as hepatic steatosis.

Sixty percent of patients with rheumatoid arthritis in Japan have used dietary supplements or health foods

We conducted a survey on the use of dietary supplements and health foods (DS/HF) in definite rheumatoid arthritis (RA) patients treated by RA specialists. Among 296 patients (male 48, female 248), 179 patients (60.5%) had experience of DS/HF use. Prevalence of DS/HF use was significantly higher in female than in male patients (63.7% versus 43.8%). Overall, patients who have used DS/HF were significantly younger than those who have not used; it was particularly notable in female patients. The proportion of current users was significantly higher in those less than 5 years from diagnosis than those who had been diagnosed for 5 years or more. Products of herbs or algae (44.1%) and components of cartilage (40.8%) were the most popular DS/HF. Primary sources of product information were family members or friends (56.4%) and advertisements in the mass media (34.1%). Of the users, 73.7% did not disclose DS/HF use to their physicians. The users expected alleviation of the symptoms (35.2%) and improvement of health (34.6%). However, 59.2% of the users were unsure of the benefits. In conclusion, physicians should be aware of the high prevalence of DS/HF usage in patients with RA in Japan.

Pendrin is a novel autoantigen recognized by patients with autoimmune thyroid diseases

CONTEXT

Pendrin is an apical protein of thyroid follicular cells, responsible for the efflux of iodide into the follicular lumen via an iodide-chloride transport mechanism. It is unknown whether pendrin is recognized by autoantibodies.

OBJECTIVE

Our objective was to examine the prevalence of pendrin antibodies in autoimmune thyroid diseases and compare with that of thyroglobulin, thyroperoxidase, TSH receptor, and sodium iodide symporter antibodies.

DESIGN

In a prevalent case-control study, we analyzed the sera of 140 autoimmune thyroid disease cases (100 with Graves' disease and 40 with Hashimoto's thyroiditis) and 80 controls (50 healthy subjects, 10 patients with papillary thyroid cancer, 10 with systemic lupus erythematosus, and 10 with rheumatoid arthritis). Pendrin antibodies were measured by immunoblotting using extract of COS-7 cells transfected with pendrin and a rabbit polyclonal pendrin antibody.

RESULTS

Pendrin antibodies were found in 81% of the cases and 9% of controls (odds ratio = 44; P < 0.0001). Among cases, pendrin antibodies were more frequent and of higher titers in Hashimoto's thyroiditis than in Graves' disease. Pendrin antibodies correlated significantly with thyroglobulin, thyroperoxidase, and sodium iodide symporter antibodies but not with TSH receptor antibodies. Pendrin antibodies were equally effective as thyroglobulin and thyroperoxidase antibodies in diagnosis of autoimmune thyroid diseases, especially Hashimoto's thyroiditis.

CONCLUSIONS

The study identifies pendrin as a novel autoantigen recognized by patients with autoimmune thyroid diseases and proposes the use of pendrin antibodies as an accurate diagnostic tool.

Expression of adipose differentiation-related protein (ADRP) and perilipin in macrophages infected with Mycobacterium leprae

Mycobacterium leprae survives and replicates within a lipid droplet stored in the enlarged phagosome of histiocytes, a typical feature of lepromatous leprosy that is thought to be an important nutrient source for the bacillus. However, the underlying mechanisms by which lipids accumulate within phagosomes remain unclear. Recently, it was revealed that the lipid droplet-associated proteins, including ADRP and perilipin, play essential roles in lipid accumulation in adipocytes or macrophages. Therefore, we attempted to examine the role of these proteins in leprosy pathogenesis. ADRP and perilipin localized to the phagosomal membrane, which contains M. leprae in skin biopsy specimens of lepromatous leprosy. ADRP expression was transiently increased after phagocytosis in THP-1 cells. However, high levels of ADRP expression persisted only when live M. leprae, but not dead bacilli or latex beads, was added. Furthermore, although peptidoglycan, a Toll-like receptor 2 ligand, suppressed the expression levels of ADRP and perilipin, M. leprae infection inhibited this suppression. These results suggest that live M. leprae has the ability to actively induce and support ADRP/perilipin expression to facilitate the accumulation of lipids within the phagosome and to further maintain a suitable environment for the intracellular survival within the macrophage.

Pycnogenol, an extract from French maritime pine, suppresses Toll-like receptor 4-mediated expression of adipose differentiation-related protein in macrophages

Adipose differentiation-related protein (ADRP) is highly expressed in macrophages and human atherosclerotic lesions. We demonstrated that Toll-like receptor (TLR) 4-mediated signals, which are involved in atherosclerosis formation, enhanced the expression of ADRP in macrophages. Lipopolysaccharide (LPS) enhanced the ADRP expression in RAW264.7 cells or peritoneal macrophages from wild-type mice, but not in macrophages from TLR4-deficient mice. Actinomycin D almost completely abolished the LPS effect, whereas cycloheximide decreased the expression at 12 h, indicating that the LPS-induced ADRP expression was stimulated at the transcriptional level and was also mediated by new protein synthesis. LPS enhanced the ADRP promoter activity, in part, by stimulating activator protein (AP)-1 binding to the Ets/AP-1 element. In addition, preceding the increase of the ADRP mRNA, LPS induced the expression of interleukin (IL)-6, IL-1alpha, and interferon-beta mRNAs, all of which stimulated the ADRP expression. Antibodies against these cytokines or inhibitors of c-Jun NH(2)-terminal kinase and nuclear factor (NF)-kappaB suppressed the ADRP mRNA level. Thus TLR4 signals stimulate the ADRP expression both in direct and indirect manners. Pycnogenol (PYC), an extract of French maritime pine, suppressed the expression of ADRP and the above-mentioned cytokines. PYC suppressed the ADRP promoter activity and enhancer activity of AP-1 and NF-kappaB, whereas it did not affect the LPS-induced DNA binding of these factors. In conclusion, TLR4-mediated signals stimulate the ADRP expression in macrophages while PYC antagonizes this process. PYC, a widely used dietary supplement, might be useful for prevention of atherosclerosis.

Expression of adipose differentiation-related protein (ADRP) is conjointly regulated by PU.1 and AP-1 in macrophages

ADRP is associated with intracellular lipid droplets. We demonstrate the regulatory mechanism for ADRP expression in RAW264.7 macrophages. The ADRP mRNA expression was stimulated by PMA, and synergistically enhanced in association with its protein level in the presence of lipids. A proteasome inhibitor protected the protein from degradation under the lipid-free conditions. One of the possible sites of the PMA action was proved to be an Ets/AP-1 element in the promoter, since mutations of this site reduced the PMA-induced promoter activity, and ligation of this element led to a significant increase in the PMA-responsiveness of homologous or heterologous promoters. Mutations of this site diminished the synergistic effect on the promoter activity induced by PMA and oleic acid, suggesting a possible interaction between this site and the downstream PPARdelta site. EMSA revealed that PU.1 and AP-1 conjointly bound to this site. The juxtaposition of the two sequences was requisite for full activity, since spacer sequences between them decreased the PMA-induced activity. PI3 kinase inhibitor was found to reduce the PMA-induced mRNA expression and promoter activity in parallel with PU.1/AP-1 complex formation on EMSA. From these results, we concluded that the Ets/AP-1 site is an important cis-acting element that regulates the ADRP gene expression in macrophages.

A novel mechanism in suppression of erythropoiesis during inflammation: a crucial role of RCAS1

A novel human tumor-associated antigen, receptor-binding cancer antigen expressed on SiSo cells (RCAS1), induces apoptosis in normal human erythroid progenitor cells, which express putative RCAS1 receptors. In the present study, we investigated a possible role of RCAS1 produced by human peripheral blood monocytes (CD14-positive cells) and monocyte-derived macrophages. RCAS1 was immunohistochemically detected in monocytes as well as macrophages. When macrophages were stimulated with lipopolysaccharide (LPS), the expression of RCAS1 was remarkably enhanced. An increased production of RCAS1 mRNA was observed in LPS-stimulated macrophages by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Soluble RCAS1 molecules were only detected in the culture supernatants obtained from LPS-stimulated macrophages. Moreover, LPS-stimulated macrophages induced cell death of erythroid progenitor cells through RCAS1 production. These results suggest that macrophages may negatively regulate erythropoiesis at least in part through the production of RCAS1 molecules, and this may contribute to the pathogenesis of the anemia seen in patients with inflammatory disorders.

Human pituitary tumor transforming gene (hPTTG) inhibits human lung cancer A549 cell growth through activation of p21(WAF1/CIP1 )

Pituitary tumor transforming gene (PTTG) is a proto-oncogene cloned from rat GH4 cells. This gene was able to induce cell transformation in vitro and is also associated with p53-dependent and -independent apoptosis. In this study, we cloned human PTTG (hPTTG) from a pituitary tumor and then stably transfected the hPTTG into HeLa and A549 cells. An overexpression of hPTTG significantly inhibited cell growth, which was determined by the adherent cell growth properties, colony formation in soft agar and [3H] thymidine incorporation, respectively, in HeLa and A549 cells. The inhibitory effect on cell growth was associated with the activation of p21WAF1/CIP1 in A549 cells, but not in HeLa cells. The hPTTG overexpression increased both the p21WAF1/CIP1 mRNA and protein expression levels as determined by both Northern and Western blot analysis, respectively, in A549 cells. The increased expression of p21WAF1/CIP1 mRNA was regulated at the transcription level and was independent on p53 expression because the luciferase activity increased after the co-transfection of hPTTG and p21WAF1/CIP1 promoter fragments with and without a p53 binding sequence. The subcellular distribution of hPTTG was dependent on cell type, and was predominantly in the nucleus in HeLa, Cos-7 and DU145 cells, but showed a diffuse distribution in both the nucleus and cytoplasm in A549, DLD-1 and NIH3T3 cells. These results indicate that an overexpression of hPTTG inhibits the cell growth due to different mechanisms, which are p21WAF1/CIP1 -dependent and -independent.

Successful treatment of pure red cell aplasia and autoimmune cytopenia with cyclosporine and prednisolone in a patient with Sjögren's syndrome

Abstract A 68-year-old woman was admitted to our hospital with xerophthalmia, xerostomia, leukopenia, and thrombocytopenia. She was diagnosed to have Sjögren's syndrome and autoimmune cytopenia. After 11 months, she was readmitted with severe anemia and reticulocytopenia. Mild hemolysis was seen, and bone marrow aspirate showed markedly decreased erythropoiesis. An association of pure red cell aplasia (PRCA) and autoimmune hemolytic anemia was diagnosed. After treatment with cyclosporine and prednisolone, her anemia dramatically improved. We discuss the mechanism of PRCA associated with Sjögren's syndrome.

Gallium-67 scintigraphy in the diagnosis and management of chronic sarcoid myopathy

The authors describe a patient with chronic sarcoid myopathy. Except for the presence of left posterior synechia, no other organ involvement was observed. Gallium-67 ((67)Ga) scintigraphy showed many intense nodular uptake areas in both the upper and lower extremities. Treatment with oral prednisolone 30 mg/day resulted in a marked improvement on (67)Ga scintigraphy. This case suggests that (67)Ga scintigraphy is useful for the differential diagnosis of systemic myopathies and also for monitoring the effect of glucocorticoid treatment.

ADRP stimulates lipid accumulation and lipid droplet formation in murine fibroblasts

Adipose differentiation-related protein (ADRP) is a lipid droplet-associated protein that is expressed early during adipose differentiation. The present study was undertaken to reveal the role of ADRP in adipose differentiation. In murine fibroblasts infected with green fluorescent protein (GFP)-ADRP fusion protein expression adenovirus vector, confocal microscopic analysis showed the number and size of lipid droplets apparently increased comparing with those of control cells. Overexpressed GFP-ADRP were mainly located at the surface of lipid droplets and appeared to be "ring-shaped." Triacylglycerol content was also significantly (P < 0.001) increased in GFP-ADRP-overexpressed cells compared with control cells. ADRP-induced lipid accumulation did not depend on adipocyte-specific gene induction, such as peroxisome proliferator-activated receptor-gamma, lipoprotein lipase, or other lipogenic genes, including acyl-CoA synthetase, fatty acid-binding protein, and fatty acid transporter. In conclusion, ADRP stimulated lipid accumulation and lipid droplet formation without induction of other adipocyte-specific genes or other lipogenic genes in murine fibroblasts. The detailed molecular mechanisms of ADRP on lipid accumulation remain to be elucidated.

Immunohistochemical analysis of RCAS1 in human pituitary adenomas

It has been reported that RCAS1 (receptor-binding cancer antigen expressed on SiSO cells) acts as a ligand for a receptor present on normal peripheral lymphocytes and induces apoptotic cell death. It is expressed in uterine and ovarian carcinomas, especially in invasive cancers. This immunohistochemical study is aimed to elucidate the expression of RCAS1 in human pituitary adenomas in order to clarify its role in their proliferative regulation and invasiveness. Five normal pituitary glands, 50 human pituitary adenomas, and one malignant glioma were subjected to immunohistochemical studies. In normal pituitary glands, immunostaining of RCAS1 and MIB-1 was not found. In malignant glioma, large numbers of cell nuclei were positive for MIB-1 (MIB-1 index: 28%), and RCAS1 was detected both in the cytoplasm and on the membrane of the tumor cells. Expression of RCAS1 was noted in 48% of pituitary adenomas immunohistochemically (60.0% of growth hormone-secreting adenomas, 60.0% of prolactin-secreting adenomas, 42.9% of adrenocorticotrophin-secreting adenomas, 40.0% of thyroid-stimulating hormone-secreting adenomas, 33.3% of nonfunctioning adenomas, and 44.4% of gonadotropin-subunit-positive adenomas). It showed no correlation with tumor type, size, and invasiveness. The statistically significant relationship between RCAS1 and MIB-1 positivity was identified in our study. These results suggest that expression of RCAS1 as well as MIB-1 positivity predict the growth potential of individual pituitary adenomas.

Glucocorticoid-induced osteoporosis: pathogenesis and management

Glucocorticoid- (GC-) induced osteoporosis and an increased risk of fractures are one of the most serious problems for patient using long-term GC therapy, such as those with rheumatoid arthritis, autoimmune diseases, inflammatory bowel diseases, bronchial asthma, and chronic lung diseases. GCs are known to affect both bone formation and resorption. In rheumatoid arthritis, the etiology of bone loss is multifactorial, including local inflammation around joints, release of bone-absorbing cytokines, physical inactivity, and malnutrition, in addition to the use of GC. Two guidelines have been published, by the American College of Rheumatology Task Force in 1966 and by the UK Consensus Group in 1998. Both guidelines recommend that patients 'receiving GC therapy at doses of 7.5 mg/day of prednisolone or more for 6 months or longer should have their bone mineral density measured and begin preventive therapies. Calcium and vitamin D supplements, sex hormone replacement, and weight-bearing exercise are the first-line therapies. For patients who are unable to take sex hormone replacement therapy (HRT), bisphosphonates are recommended by both guidelines. In this article, we briefly summarize the pathogenesis of GC-induced osteoporosis and its prevention and treatment.

Human Ad4BP/SF-1 and its related nuclear receptor

Ad4BP (or SF-1) is an essential transcriptional factor for steroidogenesis as well as for the development of the reproductive axis. We elucidated the structure of the human Ad4BP gene. The spliced variants of Ad4BP gene, ELP1 and ELP2 in mice, are unlikely to be present in humans since the analysis of the human gene revealed an in frame stop codon, 36-bp before the first ATG of Ad4BP. The promoter sequence of human Ad4BP, upstream of non-coding exon 1 was highly conserved, and E-box was also found to be essential for the transcription of human Ad4BP gene. During the process of the human Ad4BP gene cloning, we happened to obtain an Ad4BP-related gene, FTZ-F1beta which also belongs to the nuclear receptor family. We revealed cDNA structures of rat FTZ-F1beta, and found that rat has at least two types of FTZ-F1beta isoforms, which differ only by 21 amino acids length in the A/B domain. The tissue distributions of FTZ-F1beta in rat examined by RT-PCR, was found to be abundant in liver, pancreas, and gastrointestinal tracts. These results suggest that the physiological significance of FTZ-F1beta is different from that of Ad4BP.

Nicotinamide potentiates TSHR and MHC class II promoter activity in FRTL-5 cells

Here we show that nicotinamide modulates the promoter activity of rat thyrotropin (TSHR) and major histocompatibility complex (MHC) class II genes in rat FRTL-5 thyroid cells, and have identified a novel mechanism for its action. TSHR and MHC class II, are potentiated through reduced expression of a common repressor of these two genes, TSEP-1 (TSHR suppressor element binding protein-1)/YB-1. Thus we show that TSHR mRNA is increased and TSHR promoter activity was concentration-dependently activated from 0 to 40 mM nicotinamide. The promoter lengths of TSHR and MHC class II containing TSEP/YB-1 binding sites were enhanced by 40 mM nicotinamide, but not the ones deleted of these binding sites. TSEP-1/YB-1 binding to the recognition sites in both TSHR and MHC class II promoters was reduced in nicotinamide-treated FRTL-5 nuclear extracts. Nicotinamide reduced the expression of TSEP-1/YB-1 mRNA and TSEP-1/YB-1 protein in the nucleus.

Novel germline mutations of the MEN1 gene in Japanese patients with multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by tumors of the parathyroid glands, the pancreatic islet cells, and the anterior pituitary. Germline mutations of the MEN1 gene in three independent Japanese cases with MEN1 were analyzed. Case 1 has revealed a 2-bp (TA) insertion at nucleotide position 341 (341insTA) in exon 2, which shifts the reading frame such that the mutant protein has a completely different amino acid sequence from codon 78 to the premature stop codon at 119. In case 2, a nucleotide substitution, i.e., TAG in place of TGG, which encodes tryptophan at codon 198 was identified (nonsense mutation). These mutations were heterozygously present and have not been reported previously. Case 3 showed no mutations in the protein-coding exons and exon-intron junctions of the MEN1 gene by single-strand conformation polymorphism or direct sequencing of the polymerase chain reaction (PCR) fragments. We confirmed the finding that patients with MEN1 carry heterozygous germline mutations in the MEN1 gene, which is compatible with the idea that the MEN1 gene is a tumor suppressor gene. The reason why mutations in the coding region of the MEN1 gene could not be detected by PCR-based analysis in some of the MEN1 patients, e.g. case 3, needs to be clarified further.

Low level of glucocorticoid receptor messenger ribonucleic acid in pituitary adenomas manifesting Cushing's disease with resistance to a high dose-dexamethasone suppression test

OBJECTIVES

The overnight 8-mg dexamethasone suppression test is often used to differentiate Cushing's disease, due to an oversecretion of ACTH from the pituitary gland, from other kinds of Cushing's syndrome. However, a few patients with ACTH-producing pituitary adenoma show no suppression of plasma cortisol after the administration of 8 mg of dexamethasone. To clarify the relationship between the level of glucocorticoid receptor (GR) in the pituitary adenoma and the sensitivity to dexamethasone in Cushing's disease, we thus examined the levels of GR alpha and GR beta mRNAs in the pituitary adenomas in six patients who were proven at surgery to have pituitary ACTH-producing adenomas.

MATERIALS

Total RNA was extracted from six pituitary adenomas and pituitary tissue adjacent to one of the adenomas, and the mRNA levels of GR alpha, GR beta, pro-opiomelanocortin (POMC) and beta-actin in these samples were sampled by quantitative RT-PCR.

RESULTS

The GR alpha mRNA levels in the adenomas from the two patients who showed no response to the 8-mg dexamethasone suppression test were significantly lower than those in the adenomas of four patients who showed suppression. The GR beta mRNA level was much lower than that of GR alpha mRNA but not significantly different among the six adenomas.

CONCLUSIONS

These results suggest strongly that decreased expression of GR alpha in pituitary adenomas may be the major reason for the marked insensitivity to the 8-mg dexamethasone suppression test observed in two patients with Cushing's disease.

A rare case of 46,XX true hermaphroditism with hidden mosaicism with sex-determining region Y chromosome-bearing cells in the gonads

The sex-determining region Y chromosome (SRY) triggers testis determination. We report a 46,XX true hermaphrodite who had ambiguous genitalia at birth. A laparotomy at one year of age revealed this patient to have a testis on the right side and an ovotestis on the left side. By polymerase chain reaction analysis no SRY was detected in the DNA from the leukocytes but it was found in the DNA from the ovotestis. The hidden mosaicism with the Y-bearing cells in the gonads is likely the cause of the dual gonads in this patient.

Expression of an orphan nuclear receptor DAX-1 in human pituitary adenomas

OBJECTIVES

An orphan nuclear receptor, DAX-1, is known to be involved in the development and differentiation of anterior pituitary cells. The present study aimed to examine 1) whether DAX-1 is expressed in human pituitary adenomas, and 2) if it is expressed, what types of adenoma express the factor.

MATERIALS AND METHODS

Adenoma tissues examined included 18 clinically non-functioning adenomas, 14 GH-secreting adenomas and 7 PRL-secreting adenomas. The expression of the following genes were tested by reverse transcription-polymerase chain reaction (RT-PCR): DAX-1, Adrenal-4-binding protein/steroidogenic factor-1 (Ad4BP/SF-1), Pit-1, LH beta, FSH beta, gonadotrophin-releasing hormone receptor (GnRH-R), GH, PRL, and TSH beta, as well as beta-actin as a control.

RESULTS

Eleven clinically non-functioning adenomas expressed DAX-1, 10 of which also expressed Ad4BP/SF-1. Nine out of the 11 DAX-1 expressing adenomas also expressed LH beta, FSH beta and GnRH-R as well, indicating that these adenomas possessed gonadotrophic properties. Nine clinically non-functioning adenomas expressed Pit-1 as well as GH, PRL and/or TSH beta, thus having somatomammotrophic or thyrotrophic properties, 3 of which overlapped with the above DAX-1-expressing adenomas. One non-functioning adenoma expressed Ad4BP/SF1 and FSH beta but not DAX-1, and another one expressed DAX-1 and Ad4BP/SF-1 with PRL. On the other hand, all GH-secreting and PRL-secreting adenomas expressed Pit-1 and GH and/or PRL, but neither DAX-1 nor Ad4BP/SF-1.

CONCLUSIONS

The results shown here indicate that DAX-1 is expressed in the majority of human pituitary adenomas of gonadotrophic origin in parallel with Adrenal-4-binding protein/steroidogenic factor-1.

Cloning and characterization of the 4.2 kb region of the rat thyrotropin receptor promoter

We previously identified an approximately 200 bp "minimal promoter" of the rat TSH receptor (TSHR) gene which is essential for the promoter activity. In the present study, we have cloned and characterized an upstream region of the TSHR promoter to disclose additional functional element(s). We screened a rat genomic library and obtained a DNA fragment which contained a 4.2 kb 5'-flanking region. This fragment was 2.5 kb longer than that we previously studied (1.7 kb). To assess the promoter activity, chimeric plasmids containing the 4.2 kb promoter and its 5'-deletions ligated to a chloramphenicol acetyltransferase gene were transfected into thyroid and non-thyroid cells. These plasmids expressed significant promoter activity in FRTL-5 and FRT thyroid cells, but not in BRL liver cells. The strongest promoter activity was expressed by the -199 bp promoter, and the longer promoter expressed rather decreased activity. Co-expression of thyroid transcription factor-1 (TTF-1) increased the activity of the promoter region from -3187 to -199 bp, which encompassed one or two TTF-1 binding sites we previously identified, but not the -4206 bp promoter. In addition, FRTL-5 stable transfectants each having a chimeric construct were cultured in the presence or absence of TSH. All transfectants expressed higher promoter activity in the absence of TSH than in the presence of TSH, in particular, the -3187 bp plasmid expressed significantly higher activity by comparison to the -2617 and -4206 bp constructs. This result indicates that the region between -3187 and -2617 bp may contribute to TSH/cAMP-induced suppression and also suggests that the region between -4206 and -3187 bp involves the element(s) for constitutive suppression of the promoter activity. These results not only suggest that the 4.2 kb upstream region of the TSHR gene possibly contains some elements for the regulation of the gene expression, but also emphasize the importance of the minimal promoter region which we previously identified for the efficient expression of the gene.

Follicle stimulating hormone-beta subunit gene is expressed in parallel with a transcription factor Ad4BP/SF-1 in human pituitary adenomas

OBJECTIVES

A transcription factor Ad4BP/SF-1 is implicated in the differentiation of gonadotrophs in the pituitary gland, but it is not known whether human pituitary cells express this factor. The present study aimed to disclose (1) whether human pituitary adenomas express Ad4BP/SF-1, and (2) if this is the case, what kinds of adenoma express the factor.

MATERIAL

Total RNA was extracted from 23 pituitary adenomas obtained by transsphenoidal surgery, and subjected to Northern blot analyses using cDNAs of bovine Ad4BP/SF-1, porcine FSH-beta, LH-beta and glycoprotein hormone-alpha (GPH-alpha) subunts as radiolabelled probes. These adenomas included 13 clinically non-functioning adenomas, 1 GH/PRL-producing adenoma, 6 GH-producing adenomas, 2 PRL-producing adenomas and 1 ACTH-producing adenoma.

RESULTS

The expression of Ad4BP/SF-1 exactly coincided with the expression of FSH-beta. Thus 5 out of 13 clinically non-functioning adenomas expressed Ad4BP/SF-1 and only these 5 adenomas expressed FSH-beta. Interestingly, only one of the GH-producing adenomas also expressed Ad4BP/SF-1 as well as FSH-beta. GPH-alpha was expressed in 4 non-functioning adenomas and 2 hormonally functioning adenomas, but did not necessarily coincide with Ad4BP/SF-1 expression. None of the 23 adenomas we tested expressed LH-beta, probably because LH-beta-producing adenomas are rather rare.

CONCLUSIONS

The expression of FSH-beta was parallel with Ad4BP/SF-1 expression, indicating that the expression of Ad4BP/SF-1 is restricted to cells derived from gonadotroph lineages in human pituitary adenomas.

Interferon-gamma suppresses thyrotropin receptor promoter activity by reducing thyroid transcription factor-1 (TTF-1) binding to its recognition site

Interferon-gamma (IFN gamma) is known to suppress the expression of thyroid-specific genes, such as thyroglobulin, thyroid peroxidase, and the TSH receptor (TSHR). In the present study, we show that this reflects, in part, a transcriptional action mediated by thyroid transcription factor-1 (TTF-1). Thus, transfected into rat FRTL-5 cells, the activity of reporter plasmids, containing rat TSHR promoter ligated to a chloramphenicol acetyltransferase gene, was significantly suppressed in the presence of rat IFN gamma. A -199-bp promoter construct showed the greatest suppression by IFN gamma whereas a -177-bp construct, in which the TTF-1 binding site was deleted, showed less suppressibility. The suppressive effect was rat IFN gamma-specific, since human IFN alpha, -beta, and -gamma exhibited no significant effects. The effect was concentration-dependent from 3-50 U/ml. In FRT rat thyroid cells that do not express TTF-1, IFN gamma-induced suppression on the promoter activity was not observed. In addition, when the TTF-1 binding site was mutated so that TTF-1 can not bind, IFN gamma-induced suppression was significantly reduced. In gel mobility shift analyses, a protein-DNA complex formed by TTF-1 was reduced when the nuclear extract prepared from IFN gamma-treated FRTL-5 cells was used; however, expression of TTF-1 mRNA and TTF-1 protein, which were assessed by Northern blot analysis and Western blot analysis, respectively, were not affected by IFN gamma treatment of FRTL-5 cells. Instead, reduction of DNA-binding affinity of TTF-1 was evident when competition analysis was performed in gel mobility shift analysis. From these results, we conclude that IFN gamma suppresses TSHR promoter activity, in part, by reducing TTF-1 binding to its recognition site. We also raise the possibility that the suppressive effect of IFN gamma on promoter activity is mediated by additional element(s) and factor(s) downstream of the TTF-1 site.

Cyclic Cushing's disease in long-term remission with a daily low dose of bromocriptine

A 56-year-old male patient with cyclic Cushing's disease remained in a state of remission for more than one year with a relatively low dose of bromocriptine (2.5-3.75 mg/day). It has been reported that bromocriptine treatment for cyclic Cushing's disease induces only a transient remission; in the most effective cases, a relatively high dose (40 mg/day) was necessary. In the hypercortisolemic state, plasma adrenocorticotropic hormone (ACTH) and serum cortisol were not suppressed by dexamethasone and did not respond to corticotropin-releasing factor (CRF). An antehypophysectomy was not effective, even though the resected tissue contained ACTH-positive microadenomas. The present observations thus indicate the effectiveness of bromocriptine for some patients with this rare disorder.

Abnormalities of sex differentiation

Sex differentiation is determined by a cascade of events proceeding from chromosomal sex to the completion of sexual maturation at puberty. Many factors involved in this cascade have been identified. Here we focus on DAX-1, androgen receptor and cytochrome P450c17, and discuss their functions in sex differentiation. We analyzed the DAX-1 genes of two unrelated Japanese patients with congenital adrenal hypoplasia and hypogonadotropic hypogonadism using PCR amplification of genomic DNA and complete exonic sequencing, and established that congenital adrenal hypoplasia and hypogonadotropic hypogonadism result from not only inherited but also de novo mutation in the DAX-1 gene. Androgen insensitivity syndrome (AIS) is a good model to clarify the relationship between the structure and function of androgen receptor, the androgen receptor gene mutation and clinical phenotype. We analyzed 15 cases of AIS and demonstrate the structural and functional relationships of the androgen receptor. We have sequenced the CYP17 (P450c17) gene in DNA from several patients with 17 alpha-hydroxylase deficiency, reconstructed the mutations in a human P450c17 cDNA and expressed the mutant P450c17 in COSl cells to characterize the kinetic properties of 17 alpha-hydroxylase and 17,20-lyase activities. The molecular bases of cases clinically reported as 17 alpha-hydroxylase deficiency have turned out to be complete or partial combined deficiencies of 17 alpha-hydroxylase/17,20-lyase.

Aromatase in bone cell: association with osteoporosis in postmenopausal women

To clarify the possible action of adrenal androgen on bone cell, the existence, characteristics and regulation of aromatase in human osteoblast-like osteosarcoma cells (HOS) and primary cultured osteoblast-like cells from normal human bones (HO) were examined in this study. Significant positive correlation between bone mineral density (BMD) and serum dehydroepiandrosterone sulfate (DHEA-S) was found in 120 postmenopausal women (51-99 years old) but no correlation was seen between BMD and serum estradiol (E2). In subset analysis, strongly positive correlation of serum DHEA-S and estrone (E1) with BMD was observed in postmenopausal women aged less than 69 years old. Administration of DHEA to ovariectomized rat significantly increased BMD and decreased relative osteoid volume in femur. These in vivo findings strongly suggested that serum adrenal androgen may be converted to estrogen in peripheral organ, especially, osteoblast and be important steroids to maintain BMD. [3H]DHEA was converted to [3H]androstenedione and [3H]androstenedione to [3H]estrone in primary cultured human osteoblast. Osteoblast-like cells showed aromatase activity, and an apparent Km and the Vmax were 4.74 +/- 0.78 nM (mean +/- SD, n = 3) and 0.83 +/- 0.79 fmol/mg protein/h for HOS, and 4.6 +/- 2.9 nM and 279 +/- 299 fmol/mg protein/h (mean +/- SD, n = 19) for HO, respectively. The aromatase activity was significantly increased by dexamethasone in a dose-dependent manner. Reverse transcription-polymerase chain reaction analysis revealed that dexamethasone increased the transcript of P450AROM gene. Osteoblast-specific promoters were also determined. Dexamethasone and 1 alpha,25-dihydroxyvitamin D3 synergistically enhanced aromatase activity and P450AROM mRNA expression. These results demonstrate that adrenal androgen, DHEA, is converted to E1 in osteoblast by P450AROM which is positively regulated by glucocorticoid and 1 alpha,25-dihydroxyvitamin D3 and important to maintain BMD in the 6 to 7th decade, after menopause.

Cushing's disease preceding sarcoidosis

We present a 32-year-old-woman with Cushing's disease and sarcoidosis. She had been diagnosed as having Cushing's disease in 1985. She had transsphenoidal surgery followed by pituitary radiation. Subsequently her plasma cortisol level gradually decreased to normal range. In 1991, she manifested bilateral hilar lymphadenopathy on chest X-ray, erythema nodosum, subcutaneous nodules and granulomatous uveitis. From the histological findings of the skin lesions, the patient was diagnosed as having sarcoidosis. Interestingly, an inverse relationship between the disease activity of sarcoidosis and the level of serum cortisol in Cushing's disease was observed in the clinical course of this patient. Co-existence of Cushing's disease and sarcoidosis is very rare. Since the therapeutic significance of steroids in sarcoidosis has been well established, this case provides insight to the relationship between sarcoidosis and steroids.

Single strand DNA-binding proteins and thyroid transcription factor-1 conjointly regulate thyrotropin receptor gene expression

An element, -186 to -176 base pairs (bp), in the minimal TSH receptor (TSHR) promoter binds thyroid transcription factor-1 (TTF-1) and is important for both constitutive expression and TSH/cAMP-induced negative autoregulation of the TSHR in thyroid cells. An element on the noncoding strand of the TSHR, contiguous with the 5'-end of the TTF-1 element, has single strand binding activity. It is distinct from the TTF-1 site, as evidenced by competition experiments using gel shift assays; but the association of the two elements is not random. Thus, the single strand binding protein (SSBP) element also exists contiguous to the 5'-end of an upstream TTF-1 site, -881 to -866 bp; mutation of two conserved nucleotides in each SSBP element results in the loss of SSBP binding and cross-competition. Transfection experiments indicate that full, constitutive TSHR gene expression in FRTL-5 thyroid cells requires the binding of both SSBPs and TTF-1, since mutation of either element halves thyroid-specific promoter activity, whereas mutation of both decreases promoter activity to values near those of a control vector. Transfection experiments with rat liver cells support their independent activities and show that the SSBP site contributes to TSHR gene expression in non-thyroid tissue. The SSBPs function conjointly with TTF-1 in thyroid-specific, TSH/cAMP-induced negative autoregulation of the TSHR. Thus, TSH or forskolin-treated FRTL-5 cells coordinately decrease TSHR RNA levels and TSHR DNA binding to both the SSBPs and TTF-1; also the maximal TSH/cAMP-induced decrease in gene expression requires both elements. The TSH-induced effect in each case is inhibited by cycloheximide; the TSH-induced decrease in SSBP/DNA complex formation requires the presence of insulin or calf serum, exactly as does TSH-induced down-regulation of TSHR RNA levels. In sum, full, constitutive expression of the TSHR in thyroid cells requires TTF-1 and the SSBPs to bind separate, contiguous elements on the TSHR promoter. TSH/cAMP decreases the binding of each factor to its respective site, thereby decreasing TSHR gene expression. The role of the SSBP and TTF-1 sites in constitutive TSHR expression and in TSH/cAMP-induced negative regulation of the TSHR is, therefore, additive and independent.

In vivo and in vitro evidence for the production of inhibin-like immunoreactivity in human adrenocortical adenomas and normal adrenal glands: relatively high secretion from adenomas manifesting Cushing's syndrome

To clarify whether adrenal gland secretes inhibin in vivo in physiological or pathological conditions, we measured the levels of inhibin-like immunoreactivity (inhibin-LI) in adrenal veins (A-vein) and compared them with those in inferior vena cava (IVC) using blood samples obtained at catheterization of adrenal vein in the patients with adrenal adenoma manifesting Cushing's syndrome (Cs), aldosterone-producing adenoma, clinically non-functioning adenoma and normal adrenal gland. The tumor sides of A-veins in the patients with adenomas and also both sides of A-veins in subjects with normal adrenal glands showed significantly higher contents of inhibin-LI than their IVC. When the inhibin-LI secretion rate from adrenal gland was estimated by the difference between the levels of A-vein (tumor side) and IVC, Cs adenomas showed the highest secretion rate. Similarly, the tissue inhibin-LI content and the basal secretion rate of inhibit-LI from primary cultured cells were the highest in Cs adenomas. These findings indicated that normal adrenal glands and adrenocortical adenomas produced and secreted inhibin-LI into the general circulation in vivo and Cs adenomas have relatively high capacity for secreting inhibin-LI, and the present study provided the first in vivo evidence for adrenal inhibin-LI production in pathological conditions.

Characterization of an up-stream thyroid transcription factor-1-binding site in the thyrotropin receptor promoter

A thyroid transcription factor-1 (TTF-1)-binding element in the rat TSH receptor (TSHR) promoter, between -189 and -175 basepairs (bp), is important for both thyroid-specific expression and thyroid-specific TSH/cAMP autoregulation of the TSHR. The identification of an up-stream TTF-1-binding site and its relationship to the function of the down-stream TTF-1 element are the subjects of this report. Sequence analysis identifies a potential TTF-1 site at -878 bp; deoxyribonuclease-I footprinting shows that the -881 to -866 bp region is protected by recombinant TTF-1 protein and by nuclear extracts from FRTL-5 thyroid cells that contain TTF-1, but not by extracts from nonfunctioning FRT thyroid or Buffalo rat liver (BRL) cells, which have no TTF-1, or by Pax-8. FRTL-5, but not FRT or BRL cell nuclear extracts, form a specific protein-DNA complex with this region in gel mobility shift analyses; its formation is prevented by TTF-1-binding elements from the thyroglobulin promoter. The upstream TTF-1 site acts as an enhancer when coupled to a heterologous simian virus-40 promoter-chloramphenicol acetyltransferase (CAT) chimera and transfected into FRTL-5 thyroid cells. There is a greater increase, 3-vs. 2-fold (P < 0.05), when TSHR promoter-CAT chimeras, which contain the up-stream TTF-1 element, pTRCAT5'-907 or pTRCAT5'-886, as opposed to those in which it is deleted, pTRCAT5'-907 delta USTTF-1, are transfected into FRTL-5 cells or cotransfected with a TTF-1 expression vector into BRL cells, which have no endogenous TTF-1. The TTF-1-dependent activity of pTRCAT5'-907 delta USTTF-1 is the same as that of the minimal promoter, -220 to -39 bp, containing only the down-stream TTF-1 site in both cells. Transfection of chimeric TSHR-CAT plasmids with the down- and/or up-stream TTF-1 site deleted reveals that the down-stream TTF-1 element functions in the absence of the up-stream element, but function of the up-stream site requires the down-stream TTF-1 element. Like the down-stream TSHR TTF-1-binding site, the up-stream TTF-1 site is different from TTF-1 sites in the thyroglobulin and thyroid peroxidase promoter, in that it does not interact with Pax-8.(ABSTRACT TRUNCATED AT 400 WORDS)