Serum carboxy-terminal telopeptide of type I collagen levels are associated with carotid atherosclerosis in patients with cardiovascular risk factors.

Carboxy-terminal telopeptide of type I collagen (ICTP) is generated through matrix metalloproteinase (MMP)-dependent type I collagen digestion, and has been widely utilized as a biomarker for bone turnover. The fact that atherosclerotic lesions are rich in both type I collagen and MMP-producing macrophages led to the hypothesis that serum ICTP concentrations may serve as a non-invasive clinical biomarker for atherosclerosis. Therefore, the association of serum ICTP concentrations with the maximum intima-media thickness (IMT) of carotid arteries, a surrogate index of systemic atherosclerosis, or brachial-ankle pulse wave velocity (baPWV) in patients with atherosclerotic risk factors was evaluated. A total of 52 male and 65 female (mean age: 62.8 yrs) patients without renal failure, malignancies or bone diseases known to affect serum ICTP concentrations were recruited. Patients with max IMTs ≥1.1 mm showed significantly higher serum ICTP concentrations compared with patients with max IMTs <1.1 mm (3.33 ± 0.97 vs 2.82 ± 0.65 ng/mL, p<0.05). Serum ICTP concentration was also positively correlated with max IMT (p<0.001) or baPWV values (p<0.05). Multivariate analyses also revealed that serum ICTP concentrations were correlated with max IMT (p<0.001; 95% CI 0.200 to 0.454). These results suggest that serum ICTP concentrations can be used as a non-invasive biomarker for systemic atherosclerosis.

Effect of nutritional counseling and long term isomaltulose based liquid formula (MHN-01) intake on metabolic syndrome.

The isomaltulose based liquid formula (MHN-01), suppresses postprandial plasma glucose and insulin levels in healthy persons and patients with impaired glucose tolerance (IGT) or type 2 diabetes. MHN-01 intake as a part of breakfast also suppresses glucose and insulin levels after lunch, suggesting second meal effect. The objective of this study was to investigate the effects of nutritional counseling and long-term (24 weeks) MHN-01 ingestion on biomarkers of metabolic syndrome. Forty-one subjects with criteria of metabolic syndrome participated in this study composed with the control period (0-12 week) followed by nutritional counseling and the experimental period (12-36 week) followed by 200 kcal (837 kJ) of MHN-01 or dextrin-based standard balanced liquid formula (SBF) loading as a part of breakfast. In 16 of 41 subjects became to out of criteria for liquid formula loading study during control period (unqualified group). In the unqualified group, several biomarkers were improved. In experimental period, serum HbA1c levels significantly increased in SBF group (n = 12) but did not change in MHN-01 group (n = 10). Thus, intake of 837 kJ MHN-01 as a part of breakfast may be effective for suppression of deteriorating glucose metabolism in metabolic syndrome.

An attempt to create a treatment algorithm of central adrenal insufficiency using CRH test, DHEA-S and clinical evaluation.

Objective : To examine diagnostic performance of corticotropin-releasing hormone (CRH) test combined with baseline dehydroepiandrosterone sulfate (DHEA-S) in patients with a suspect of central adrenal insufficiency. Methods : Patients (n=215) requiring daily or intermittent hydrocortisone replacement, or no replacement were retrospectively checked with their peak cortisol after CRH test and baseline DHEA-S. Results :  None of 106 patients with the peak cortisol ≥ 17.5 µg / dL after CRH test required replacement, and all 64 patients with the peak cortisol < 10.0 µg / dL required daily replacement. Among 8 patients with 10.0 µg / dL ≤ the peak cortisol < 17.5 µg / dL and baseline DHEA-S below the reference range, 6 patients required daily replacement and 1 patient was under intermittent replacement. Among 37 patients with 10.0 µg / dL ≤ the peak cortisol < 17.5 µg / dL and baseline DHEA-S within the reference range, 10 and 6 patients were under intermittent and daily replacement, respectively. Conclusions : No patients with the peak cortisol ≥ 17.5 µg / dL required hydrocortisone replacement, and all patients with the peak cortisol below 10.0 µg / dL required daily replacement. Careful clinical evaluation was required to determine requirement for replacement in patients with 10.0 µg / dL ≤ the peak cortisol < 17.5 µg / dL even in combination with baseline DHEA-S. J. Med. Invest. 69 : 287-293, August, 2022.

[Diabetic osteoarthropathy].

It is well-known that osteoarthropathy is one of common problems in diabetic patients. Limitation of joint mobility and painful disorder associated with inflammation of tendons and sheaths are more frequently observed on hands and shoulders. Most of these complications are not specific for diabetes mellitus, but more often in diabetic populations than in non-diabetic populations. On the other hand, destructive bone change due to diabetic polyneuropathy are commonly observed on lower extremities. To control neuroarthropathy is important for prevention of the following diabetic ulcer and gangrene. Because diabetic osteoarthropathy is mostly irreversible, early diagnosis is necessary to prevent its progression.

Growth factors and beta cell replication.

Recent studies have demonstrated that human islet allograft transplantation can be a successful therapeutic option in the treatment of patients with Type I diabetes. However, this impressive recent advance is accompanied by a very important constraint. There is a critical paucity of pancreatic islets or pancreatic beta cells for islet transplantation to become a large-scale therapeutic option in patients with diabetes. This has prompted many laboratories around the world to invigorate their efforts in finding ways for increasing the availability of beta cells or beta cell surrogates that potentially could be transplanted into patients with diabetes. The number of studies analyzing the mechanisms that govern beta cell proliferation and growth in physiological and pathological conditions has increased exponentially during the last decade. These studies exploring the role of growth factors, intracellular signaling molecules and cell cycle regulators constitute the substrate for future strategies aimed at expanding human beta cells in vitro and/or in vivo after transplantation. In this review, we describe the current knowledge on the effects of several beta cell growth factors that have been shown to increase beta cell proliferation and expand beta cell mass in vitro and/or in vivo and that they could be potentially deployed in an effort to increase the number of patients transplanted with islets. Furthermore, we also analyze in this review recent studies deciphering the relevance of these specific islet growth factors as physiological and pathophysiological regulators of beta cell proliferation and islet growth.

Acute effect of fast walking on postprandial blood glucose control in type 2 diabetes.

PURPOSE: Several guidelines have recently recommended exercise for prevention and treatment of type 2 diabetes. However, determining the optimum exercise conditions, e.g., the intensity, amount, frequency, and type of exercise, is difficult, particularly by patients themselves. We have investigated the acute effect of fast walking on postprandial blood glucose levels among patients with type 2 diabetes. METHODS: Fourteen patients diagnosed with type 2 diabetes at least 1 year previously were eligible for inclusion in this study during educational hospitalization. Three walking programs, natural walking (walking at a natural speed), 10 % fast walking, and 20 % fast walking, were performed 1 h after lunch in a randomized sequence with a washout period of 1 day. Walking time was 30 min in all the programs. Primary outcome was determined by self-monitoring of blood glucose. Blood glucose levels were measured before walking, after walking for 15 min, and at the end of walking. Heart rate and systolic and diastolic pressure were also measured for safety reasons. RESULTS: All the participants completed the study with no adverse effects. Compared with natural walking, fast walking markedly improved postprandial glucose excursion in an intensity-dependent manner without any adverse effects. CONCLUSION: Fast walking acutely reduced postprandial blood glucose levels among patients with type 2 diabetes. Our method has major implications for the practice of diabetes education in clinical rehabilitation.

Characterization of mice doubly transgenic for parathyroid hormone-related protein and murine placental lactogen: a novel role for placental lactogen in pancreatic beta-cell survival.

Transgenic overexpression of either parathyroid hormone-related peptide (PTHrP) or mouse placental lactogen type 1 (mPL1) in pancreatic beta-cells, using the rat insulin II promoter (RIP), results in islet hyperplasia either through prolonged beta-cell survival or through increased beta-cell proliferation and hypertrophy, respectively. For determining whether the two proteins might exert complementary, additive, or synergistic effects on islet mass and function when simultaneously overexpressed in beta-cells in vivo, RIP-PTHrP and RIP-mPL1 mice were crossed to generate mice doubly transgenic for PTHrP and mPL1. These double-transgenic mice displayed marked islet hyperplasia (threefold), hypoglycemia, increased beta-cell proliferation (threefold), and resistance to the diabetogenic and cytotoxic effects of streptozotocin compared with their normal siblings. Although the phenotype of the double-transgenic mice was neither additive nor synergistic relative to their single-transgenic counterparts, it was indeed complementary, yielding the maximal salutary phenotypic features of both individual transgenes. Finally, mPL1, for the first time, was shown to exert a protective effect on the survival of beta-cells, placing it among the few proteins that can improve function and proliferation and prolong the survival of beta-cells. Placental lactogen 1 is an attractive target for future therapeutic strategies in diabetes.

Diabetic conditions differentially affect the endothelial function, arterial stiffness and carotid atherosclerosis.

AIM: The levels of fasting and postprandial plasma glucose, HbA1c and other risk factors for atherosclerosis have distinct effects in patients with and those without diabetes mellitus. The aim of this study was to determine the impact of diabetic surrogate markers on the endothelial function, arterial stiffness and carotid atherosclerosis in individuals with and without diabetes. METHODS: A total of 320 Japanese subjects(mean age: 61.2 ± 12.1 years) were recruited in this study. Demographic, clinical and laboratory parameters, including 75 g OGTT(155 subjects) results, were examined. The endothelial function was evaluated according to the flow-mediated vasodilation of the brachial artery(%FMD). In addition, arterial stiffness was evaluated according to the brachial-ankle pulse wave velocity(baPWV), and carotid atherosclerotic changes were estimated according to the maximum intima-media thickness(max-IMT) and resistive index of the common carotid artery(CCA-RI). A multiple regression analysis was performed to identify independent determinants of these vascular surrogate markers. RESULTS: None of the glucose-related parameters were associated with the %FMD. In contrast, the presence of T2DM, the HbA1c level and an increased plasma glucose level at 60 minutes during 75 g OGTT were associated with an increased baPWV. The HbA1c level was also correlated with an increased max-IMT. The fasting plasma glucose(FPG) level and the presence of T2DM correlated with an increased CCA-RI. In the subjects with T2DM, the protective effects of high-density lipoprotein cholesterol(HDL-C) on the %FMD and baPWV were abolished. CONCLUSIONS: Various glucose metabolism parameters have different effects the degree of arterial stiffness and presence of carotid atherosclerosis, but not the endothelial function, suggesting that pharmacological intervention has the potential to preserve the endothelial function in diabetic individuals. In addition, the presence of T2DM blunts the vascular protective effects of HDL-C on the endothelial function and progression of arterial stiffness.

Serum carboxy-terminal telopeptide of type I collagen (ICTP) as a surrogate marker for vulnerable plaques in atherosclerotic patients: a pilot study.

Evaluation of atherosclerotic plaques depends on invasive intravascular ultrasonography (IVUS). Carboxy-terminal telopeptide of type I collagen (ICTP) is produced by matrix metalloproteinase (MMP)-dependent digestion of type I collagen. Because vulnerable plaques are rich in type I collagen and MMPs from macrophages, we examined the association between serum ICTP and coronary plaques in patients with coronary disease. We recruited 46 men and 17 women without renal failure or bone diseases affecting serum ICTP, who underwent coronary IVUS. Serum ICTP levels were higher in patients with coronary plaques containing more than 10% necrotic core area than in patients with less than 10% necrotic core area. A positive correlation was found between serum ICTP and necrotic core area. Only serum ICTP was positively correlated with necrotic core area by multivariate analysis (p < 0.05). These results suggest that serum ICTP can be used as a non-invasive marker of vulnerable plaques in atherosclerotic patients.

Inhibition of thrombin action ameliorates insulin resistance in type 2 diabetic db/db mice.

The binding of thrombin to its receptor stimulates inflammatory cytokines including IL-6 and monocyte chemoattractant protein-1 (MCP-1); both are associated with the development of insulin resistance. Because increased adiposity enhanced the expression of coagulation factor VII that stimulates the coagulation pathway in adipose tissue, we tested whether the inhibition of thrombin action ameliorates insulin resistance in obese diabetic (Lpr(-/-):db/db) mice. The 4-wk administration of argatroban, a selective thrombin inhibitor, reduced fasting plasma glucose and ameliorated insulin resistance in these mice. It also reduced adipocyte size and macrophage infiltration into adipose tissue. The aberrant gene expression of MCP-1, IL-6, adiponectin, and factor VII and suppressed insulin receptor substrate-1-Akt signaling in adipose tissue of db/db mice were reversed by argatroban treatment. These results demonstrate that increased adiposity enhances the production of thrombin in adipose tissue by stimulating factor VII expression and suggest that increased thrombin activity in adipose tissue plays an important role in the development of insulin resistance via enhancing MCP-1 production, leading to macrophage infiltration and insulin receptor substrate-1-Akt pathway inactivation.

Lactogens promote beta cell survival through JAK2/STAT5 activation and Bcl-XL upregulation.

One of the goals in the treatment for diabetes is to enhance pancreatic beta cell function, proliferation, and survival. This study explores the role of lactogenic hormones, prolactin (PRL) and placental lactogen (PL), in beta cell survival. We have previously shown that transgenic mice expressing mouse placental lactogen-1 (mPL1) in beta cells under the rat insulin II promoter (RIP) are resistant to the diabetogenic and cytotoxic effects of streptozotocin (STZ) in vivo. The current study demonstrates that lactogens protect rat insulinoma (INS-1) cells and primary mouse beta cells against two distinct beta cell death inducers, STZ and dexamethasone (DEX), in vitro. Further, we identify the mechanism through which lactogens protect beta cells against DEX-induced death. The signaling pathway mediating this protective effect is the janus-activated-kinase-2/signal transducer and activator of transcription-5 (JAK2/STAT5) pathway. This is demonstrated in INS-1 cells and primary mouse beta cells using three separate approaches, pharmacological inhibitors, JAK2-specific siRNAs and a dominant-negative STAT5 mutant. Furthermore, lactogens specifically and significantly increase the anti-apoptotic protein Bcl-XL in insulinoma cells and mouse islets. Bcl-XL-specific siRNA significantly inhibits lactogen-mediated protection against DEX-induced beta cell death. We believe this is the first direct demonstration of lactogens mediating their protective effect through the JAK2/STAT5 pathway in the beta cell and through Bcl-XL in any cell type.

Protein kinase C-zeta activation markedly enhances beta-cell proliferation: an essential role in growth factor mediated beta-cell mitogenesis.

OBJECTIVE: Diabetes results from a deficiency of functional beta-cells. Previous studies have identified hepatocyte growth factor (HGF) and parathyroid hormone-related protein (PTHrP) as two potent beta-cell mitogens. The objective of this study is to determine 1) whether HGF and PTHrP have additive/synergistic effects on beta-cell growth and proliferation; 2) the signaling pathways through which these growth factors mediate beta-cell mitogenesis; and 3) whether activation of this/these signaling pathway(s) enhances human beta-cell replication. RESEARCH DESIGN AND METHODS: We generated and phenotypically analyzed doubly transgenic mice overexpressing PTHrP and HGF in the beta-cell. INS-1 and primary mouse and human islet cells were used to identify mitogenic signaling pathways activated by HGF and/or PTHrP. RESULTS: Combined overexpression of HGF and PTHrP in the beta-cell of doubly transgenic mice did not result in additive/synergistic effects on beta-cell growth and proliferation, suggesting potential cross-talk between signaling pathways activated by both growth factors. Examination of these signaling pathways in INS-1 cells revealed atypical protein kinase C (PKC) as a novel intracellular target activated by both HGF and PTHrP in beta-cells. Knockdown of PKC zeta, but not PKC iota/lambda, expression using specific small-interfering RNAs blocked growth factor-induced INS-1 cell proliferation. Furthermore, adenovirus-mediated delivery of kinase-dead PKC zeta completely inhibited beta-cell proliferation in primary islet cells overexpressing PTHrP and/or HGF. Finally, adenovirus-mediated delivery of constitutively active PKC zeta in mouse and human primary islet cells significantly enhanced beta-cell proliferation. CONCLUSIONS: PKC zeta is essential for PTHrP- and HGF-induced beta-cell proliferation. PKC zeta activation could be useful in therapeutic strategies for expanding beta-cell mass in vitro and in vivo.

Multiple Endocrine Neoplasms in a Patient with AL Amyloidosis-Associated Plasma Cell Dyscrasia.

Reports on patients with systemic amyloidosis-associated plasma cell dyscrasia (PCD) who have multiple endocrine tumors are very rare. Here we describe such a case. The patient was a 74-yr-old man with amyloid light-chain (AL) amyloidosis-associated PCD who had a null-cell adenoma of the pituitary and a latent papillary carcinoma of the thyroid gland. as well as a tubular adenoma of the sigmoid colon. The amyloid protein deposits reacted with the antibody to the n-immunoglobulin light chain. Since PCD by itself may be a risk factor for the development of subsequent neoplasms, the careful clinical evaluation of PCD patients is recommended.