Role of growth hormone signaling pathways in the development of atherosclerosis.

OBJECTIVE: The direct actions of growth hormone (GH) in the development of atherosclerosis are unclear. The goal of this study was to characterize GH-induced changes in expression of signaling pathway elements and other proteins that may be related to atherosclerosis. METHODS: Human umbilical vein endothelial cells (HUVEC) and THP-1, a human acute monocytic leukemia cell line, were stimulated by exposure to 10-9 M or 10-8 M human GH with or without pretreatment with a mitogen-activated protein kinase kinase (MEK) 1 inhibitor. Levels of transcripts encoding vascular cell adhesion molecule (VCAM) -1, E-selectin, monocyte chemotactic protein (MCP-1), interleukin (IL) -6, and IL-8 were investigated by reverse transcription (RT) -PCR. For the quantitative adhesion assay, THP-1 cells or human primary monocytes were fluorescently labeled with 3'-O-acetyl-2',7'-bis(carboxyethyl) -4 diacetoxymethyl ester (BCECF/AM). HUVEC treated with human GH were co-incubated with BCECF-labeled THP-1 cells. One hour later, the number of BCECF-labeled THP-1 cells was assessed. An equivalent experiment was performed using BCECF-labeled primary monocytes, and the number of monocytes adhering to HUVEC was counted. RESULTS: Treatment with hGH increased the levels of E-selectin- and VCAM-1-encoding mRNAs in HUVEC. This effect was attenuated by pretreatment with a MEK1 inhibitor. Furthermore, hGH treatment increased adhesion of BCECF-labeled THP-1 cells or primary monocytes to HUVEC, and this effect was attenuated by pretreatment with a MEK1 inhibitor. CONCLUSIONS: VCAM-1 and E-selectin expression was stimulated by GH via the mitogen-activated protein kinase pathway, resulting in augmented adhesion of THP-1 cells and monocytes to HUVEC. These data suggested that GH directly stimulates the development of atherosclerosis.

A case of severe acute necrotizing pancreatitis after administration of sitagliptin.

A 55-year-old Japanese man with a 3-year history of type 2 diabetes mellitus was admitted to our hospital for upper abdominal pain. Control of diabetes mellitus was good with voglibose and metformin, with sitagliptin added to this regimen 8 months prior. His pancreatic enzyme levels were elevated, and abdominal computed tomography (CT) showed diffuse pancreatic swelling with fluid accumulation and ascites of CT grade 3. The patient was diagnosed with severe acute pancreatitis. There were no obvious causes for pancreatitis except the recently administered sitagliptin. Since incretin-related drugs entered the market, the number of incretin-related drugs prescriptions rapidly increased and so did the incidence of pancreatitis. There are several reports suggesting the correlation between incretin-related drugs and pancreatitis, such as a report based on data obtained from the United States Food and Drug Administration (FDA) which revealed a significant correlation between the administration of exenatide or sitagliptin and pancreatitis. However, there also is a report that denied the evidence for such in a large cohort study. The relation between incretin based drugs and pancreatitis is still controversial.

Thyroid storm associated with Graves' disease covered by diabetic ketoacidosis: A case report.

BACKGROUND: Thyroid storm is a condition in which multiple organ dysfunction results from failure of the compensatory mechanisms of the body owing to excessive thyroid hormone activity induced by some factors in patients with thyrotoxicosis. While diabetic ketoacidosis (DKA) is an important trigger for thyroid storm, simultaneous development of DKA and thyroid storm is rare. CASE PRESENTATION: A 59-year-old woman with no history of either diabetes mellitus or thyroid disease presented to our hospital because of developing nausea, vomiting and diarrhea for 2 days. Physical examination showed mild disturbance of consciousness, fever, and tachycardia. There were no other signs of thyrotoxicosis. Laboratory studies revealed elevation of random blood glucose and glycosylated hemoglobin, strongly positive of urine acetone, and metabolic acidosis. Since DKA was diagnosed, we initiated the patient on treatment with administration of insulin and adequate fluid replacement. Although the hyperglycemia and acidosis were immediately relieved, the disturbance of consciousness and tachycardia remained persistent. Levels of FT3 and FT4 were extremely high and TSH was below the detectable limit. TRAb was positive. The thyroid storm score of Burch & Wartofsky was 75/140, and the thyroid storm diagnostic criteria of the Japan Thyroid Association were satisfied. Oral administration of thiamazole, potassium iodide and propranolol resulted in immediate relief of the tachycardia. DISCUSSION: We encountered a case of thyroid storm associated with Graves' disease covered by DKA. Thyroid storm and DKA are both potentially fatal, and the prognosis varies depending on whether or not these conditions are detected and treated sufficiently early. The thyroid storm diagnostic criteria prepared in 2008 by the Japan Thyroid Association are very simple as compared to the Burch & Wartofsky scoring system for thyroid storm. The Japanese criteria may be useful in the diagnosis of this condition since they enable clinicians to identify a broad range of cases with thyroid storm. When dealing with cases of DKA or thyroid storm, it seems essential to bear in mind the possibility of the coexistence of these two diseases.

Influence of fatty liver on plasma small, dense LDL- cholesterol in subjects with and without metabolic syndrome.

AIM: Small, dense low density lipoprotein (sLDL) is known as an atherogenic lipoprotein and is often associated with metabolic syndrome (MS). A high frequency of sLDL is found in hypertriglyceridemic subjects. Also, fatty liver (FL) is often associated with MS; therefore, we studied whether the association of FL increases sLDL- cholesterol (C) in subjects with MS. METHODS: In total, 207 patients were enrolled in this study and FL was estimated by echogram. The presence of MS was diagnosed according to the Japanese Guidelines for the Definition of Metabolic Syndrome. RESULTS: sLDL-C and sLDL-C/LDL-C in the MS group were higher than in the non-MS group. Also, sLDL-C and sLDL-C/LDL-C in the FL group were higher than in the non-FL group. The simple correlation coefficient (r) between plasma triglyceride and sLDL-C or sLDL-C/LDL-C in all subjects was 0.36 and 0.51. In the MS group, r values were 0.32 and 0.52 while, in the non-FL group, r was 0.32 and 0.38, respectively. Two-way ANOVA revealed that FL was a powerful determinant of plasma sLDL-C and sLDL-C/LDL-C, but MS was not. When we divided all subjects into four groups, i.e., MS(-)FL(-), MS(-)FL(+), MS(+)FL(-) and MS(+)FL(+), sLDL-C/LDL-C of MS(+)FL(+) was significantly higher than all other groups. CONCLUSION: Association of MS and FL significantly increased sLDL-C and sLDL-C/LDL-C. The significant relationship between sLDL-C/LDL-C and plasma triglyceride in the FL group indicates that FL may produce triglyceriderich VLDL, a precurser of sLDL, thereby contributing to the appearance of sLDL particles in the plasma of MS patients with FL.

Small, dense LDL and high-sensitivity C-reactive protein (hs-CRP) in metabolic syndrome with type 2 diabetes mellitus.

AIM: To clarify the clinical significance of small,dense LDL (sLDL) in the metabolic syndrome associated with type 2 diabetes. METHODS: One hundred and ten healthy non-diabetic and non-metabolic syndrome subjects (58 male/52 female), 77 non-metabolic diabetic subjects (62/15), 58 non-diabetic metabolic subjects (25/33), and 46 metabolic diabetic subjects (29/17) were enrolled in this study. RESULTS: The subjects with metabolic syndrome (both with and without type 2 diabetes) had significantly higher fasting blood glucose, total-cholesterol (C), LDL-C, triglyceride, sLDL-C and hs-CRP levels than non-metabolic and non-diabetic subjects. HDL-C levels were significantly decreased in the former compared to the latter. Among the metabolic syndrome subjects, those with type 2 diabetes had significantly higher fasting blood glucose, systolic blood pressure and hs-CRP values than those without diabetes. sLDL-C, LDL-C and hs-CRP were the highest and HDL-C was lowest in the metabolic syndrome with diabetes group. A multiple regression analysis revealed the most significant determinant of sLDL-C to be LDL-C, followed by HDL-C, total-C, metabolic syndrome, type 2 diabetes mellitus, and triglyceride. CONCLUSION: Metabolic syndrome is a significant determinant of the plasma sLDL-C level. Hs-CRP was the highest in the metabolic syndrome patients with type 2 diabetes. Therefore, type 2 diabetes may further increase the risk of coronary artery disease in the metabolic syndrome subjects through cardiovascular inflammation.

Graves' disease with intractable diarrhea, chylous ascites, and chylothorax: a case report.

A 50-year-old woman was admitted to our hospital because of severe diarrhea, irritableness, and severe pitting edema of the legs. The patient had been well until 5 years before admission, when a tremor and tachycardia developed and a diagnosis of Graves' disease was made. Treatment with methimazole was effective in reducing her tremor and tachycardia; however, she was often nonadherent with her antithyroid medication because of improvement of her symptoms. On admission, a thyroid swelling, exophthalmos, a pleural effusion, and ascites were observed. The results of thyroid function tests (free triiodothyronine: 21.5 pg/mL; free thyroxine: 7.17 ng/dL; thyroid-stimulating hormone (TSH): <0.01 microIU/mL; TSH receptor antibodies: 95.9%) were consistent with Graves' disease. Biochemical analysis of pleural and ascitic fluid was consistent with chylothorax and chylous ascites, respectively. Serum calcium, total protein, and albumin were very low. Her symptoms and signs except severe diarrhea, edema, pleural effusion, and ascites disappeared after receiving intravenous drip infusion of fluid replacement, and methimazole and iodine. Because of malnutrition, she was given a high-calorie intravenous infusion. Three months after admission, her pleural effusion and ascites began to improve, as did her diarrhea and hypoalbuminemia. An appropriate treatment of Graves' disease is crucial to avoid serious sequelae of longstanding, poorly controlled hyperthyroidism.

Effects of valsartan on inflammatory and oxidative stress markers in hypertensive, hyperglycemic patients: an open-label, prospective study.

BACKGROUND: Diabetes mellitus and hypertension are aggravated by activation of the renin-angiotensin system caused by increased oxygen stress and local inflammatory responses. Several studies have suggested that angiotensin II type 1 receptors can reduce inflammatory markers (high-sensitivity C-reactive protein [hs-CRP], interleukin [IL]-6, IL-18, soluble vascular cell adhesion molecule [VCAM]-I, and l-selectin) and oxidative stress markers (urinary 8-hydroxy-7,8-dihydro-2'-deoxyguanosine [8-OHdG] and 8-epi-prostaglandin F2α [8-isoprostane]) in hypertensive patients. OBJECTIVE: The aim of this study was to assess the effects of valsartan, an angiotensin II receptor blocker, on inflammatory and oxidative stress markers in hypertensive patients with mild diabetes or impaired glucose tolerance. METHODS: In this open-label, prospective study, hypertensive patients aged >20 years with mild diabetes (requiring treatment by diet alone or an oral hypoglycemic), seen on an outpatient basis at the Division of Diabetes, Metabolism, and Endocrinology, Omori Hospital, Toyko, Japan, who were receiving a therapeutic dietary regimen for ≥1 month in the treatment of diabetes or hypertension, were eligible for enrollment. Blood pressure, inflammatory markers (hs-CRP, IL-6, IL-18, VCAM-1, and L-selectin), and oxidative stress markers (urinary 8-OHdG and 8-isoprostane) were monitored before treatment commencement with valsartan (40-80 mg/d) and after 3 months of treatment. RESULTS: A total of 26 patients (18 men, 8 women; mean [SD] age, 57.7 [11.3] years; mean [SD] weight, 65.3 [13.1] kg) were enrolled in the study. After 3 months of treatment, patients' mean (SD) blood pressure had significantly decreased from 153.1 (11.2)/88.3 (11.4) to 143.7 (13.7)/85.2 (9.0) mm Hg (P < 0.05). Among the inflammatory and oxidative stress markers, hs-CRP, VCAM-1, and urinary 8-OHdG concentrations decreased significantly from 0.231 (0.199) to 0.134 (0.111) mg/dL (P = 0.043), 471.1 (193.9) to 403.2 (135.2) ng/mL (P = 0.012), and 12.12 (5.99) to 8.07 (3.36) ng/mg · creatinine (P = 0.001), respectively. The reductions in these markers were observed in patients regardless of whether or not their glycosylated hemoglobin (HbA1c) concentration improved (defined as a decrease of ≥1% in HbA1c). CONCLUSION: This small, open-label, prospective study found that a 3-month treatment with valsartan was associated with a significant reduction of hs-CRP, VCAM-1, and urinary 8-OHdG concentrations independent of improvement in HbA1c concentration in these hypertensive patients with hyperglycemia.

Role of protein kinase C-angiotensin II pathway for extracellular matrix production in cultured human mesangial cells exposed to high glucose levels.

The intrarenal renin-angiotensin system has been implicated in the pathogenesis of diabetic nephropathy. This study investigates the mechanisms for glucose-induced increase in angiotensin II (AII) production by human mesangial cells (MCs) in relation to protein kinase C (PKC). We also examine whether locally produced AII mediates extracellular matrix protein production in high-glucose conditions. Human MCs were cultured in 5 or 33 mmol/l glucose for 8 days, and were incubated with or without 5 mmol/l GFX, a PKC inhibitor, 0.1 micromol/l candesartan cilexetil (CC), a specific type 1 AII receptor antagonist, for another 24 h. In addition, MCs grown in 5 mmol/l glucose were incubated with 0.1 micromol/l phorbol-12,13-dibutyrate (PDBu) for 24 h. AII, TGF-beta1, fibronectin and type IV collagen in the culture media were measured by ELISA. The amount of AII secreted from MCs exposed to high-glucose levels was significantly greater (P<0.01) than that in normal glucose levels. The increase in AII production was completely prevented by GFX. The addition of PDBu mimicked the effect of glucose on AII production. The glucose-induced increases in the production of TGF-beta1, fibronectin and type IV collagen were partially, but significantly restored (P<0.01) by CC, while GFX totally abolished these effects of glucose. These results suggest that elevated glucose levels stimulate AII production via mechanisms dependent on glucose-induced PKC activation in human MCs, and that locally produced AII partly mediates the increase in mesangial matrix synthesis in high-glucose conditions.

Transforming growth factor-beta-1 latency-associated peptide and soluble betaglycan prevent a glucose-induced increase in fibronectin production in cultured human mesangial cells.

This study was performed to investigate the effects of transforming growth factor-beta1 (TGF-beta1) latency-associated peptide (LAP) and betaglycan on TGF-beta1 activity, and on the glucose-induced overproduction of fibronectin in cultured human mesangial cells (MCs). We found that recombinant LAP and recombinant soluble betaglycan decrease the active form of TGF-beta1, measured by ELISA, in a dose-dependent manner in a cell-free system. The effective dosages of LAP and soluble betaglycan for a 50% reduction were approximately 20- and 75-fold of the TGF-beta1 concentration, respectively. The active form of TGF-beta1 in the media secreted from MCs was significantly (p < 0.01) reduced by the addition of 10 nmol/l LAP and 10 nmol/l soluble betaglycan with no significant change in total (active + latent) TGF-beta1. Recombinant LAP and soluble betaglycan also inhibited a recombinant TGF-beta1-stimulated increase in fibronectin production in MCs. Furthermore, the glucose-induced increase in fibronectin secreted from MCs was significantly (p < 0.01) suppressed by concomitant incubation with LAP or soluble betaglycan, while these agents had no effect on fibronectin production under physiological glucose concentrations. These results indicate that recombinant LAP and soluble betaglycan suppress the glucose-induced overproduction of fibronectin presumably via inhibition of TGF-beta1 activity in MCs. Further in vivo studies are needed to define the possible beneficial effects of these agents in diabetic nephropathy.