The Role of the Vascular System in Degenerative Diseases: Mechanisms and Implications.

Degenerative diseases, encompassing a wide range of conditions affecting various organ systems, pose significant challenges to global healthcare systems. This comprehensive review explores the intricate interplay between the vascular system and degenerative diseases, shedding light on the underlying mechanisms and profound implications for disease progression and management. The pivotal role of the vascular system in maintaining tissue homeostasis is highlighted, as it serves as the conduit for oxygen, nutrients, and immune cells to vital organs and tissues. Due to the vital role of the vascular system in maintaining homeostasis, its dysfunction, characterized by impaired blood flow, endothelial dysfunction, and vascular inflammation, emerges as a common denominator of degenerative diseases across multiple systems. In the nervous system, we explored the influence of vascular factors on neurodegenerative diseases such as Alzheimer's and Parkinson's, emphasizing the critical role of cerebral blood flow regulation and the blood-brain barrier. Within the kidney system, the intricate relationship between vascular health and chronic kidney disease is scrutinized, unraveling the mechanisms by which hypertension and other vascular factors contribute to renal dysfunction. Throughout this review, we emphasize the clinical significance of understanding vascular involvement in degenerative diseases and potential therapeutic interventions targeting vascular health, highlighting emerging treatments and prevention strategies. In conclusion, a profound appreciation of the role of the vascular system in degenerative diseases is essential for advancing our understanding of degenerative disease pathogenesis and developing innovative approaches for prevention and treatment. This review provides a comprehensive foundation for researchers, clinicians, and policymakers seeking to address the intricate relationship between vascular health and degenerative diseases in pursuit of improved patient outcomes and enhanced public health.

Alzheimer's Amyloid ß Peptide Induces Angiogenesis in an Alzheimer's Disease Model Mouse through Placental Growth Factor and Angiopoietin 2 Expressions.

Increased angiogenesis, especially the pathological type, has been documented in Alzheimer's disease (AD) brains, and it is considered to be activated due to a vascular dysfunction-mediated hypoxic condition. To understand the role of the amyloid ß (Aß) peptide in angiogenesis, we analyzed its effects on the brains of young APP transgenic AD model mice. Immunostaining results revealed that Aß was mainly localized intracellularly, with very few immunopositive vessels, and there was no extracellular deposition at this age. Solanum tuberosum lectin staining demonstrated that compared to their wild-type littermates, the vessel number was only increased in the cortex of J20 mice. CD105 staining also showed an increased number of new vessels in the cortex, some of which were partially positive for collagen4. Real-time PCR results demonstrated that placental growth factor (PlGF) and angiopoietin 2 (AngII) mRNA were increased in both the cortex and hippocampus of J20 mice compared to their wild-type littermates. However, vascular endothelial growth factor (VEGF) mRNA did not change. Immunofluorescence staining confirmed the increased expression of PlGF and AngII in the cortex of the J20 mice. Neuronal cells were positive for PlGF and AngII. Treatment of a neural stem cell line (NMW7) with synthetic Aß1-42 directly increased the expression of PlGF and AngII, at mRNA levels, and AngII at protein levels. Thus, these pilot data indicate that pathological angiogenesis exists in AD brains due to the direct effects of early Aß accumulation, suggesting that the Aß peptide regulates angiogenesis through PlGF and AngII expression.

Associations between dairy consumption and the physical function in Japanese community-dwelling older adults: The Shimane CoHRE study.

OBJECTIVES: We investigated sex differences in the associations between dairy consumption and the physical function among community-dwelling older adults. METHODS: Six hundred and fifty-six older adults (75.6 ± 6.4 years old) participated in this study. Dairy consumption (5-item Likert score) and the physical function (gait speed, handgrip strength, and skeletal muscle mass) were measured. The linear and quadratic associations between dairy consumption and the physical function measures were examined by a multiple linear regression analysis adjusted for covariates. RESULTS: Among women, an increased dairy consumption was significantly linearly associated with greater hand-grip strength and faster gait speed (both p<0.05) after adjusting for covariates. Among men, dairy consumption was not associated with the physical function measures. Dairy consumption was not associated with the muscle mass in either sex. CONCLUSIONS: Increased dairy consumption was associated with a superior physical function in older women.

iTRAQ-Based Proteomic Analysis of APP Transgenic Mouse Urine Exosomes.

Alzheimer's disease (AD) is a common dementia disease in the elderly. To get a better understanding of the pathophysiology, we performed a proteomic analysis of the urine exosomes (U-exo) in AD model mice (J20). The polymer precipitation method was used to isolate U-exo from the urine of 3-month-old J20 and wild-type (WT) mice. Neuron-derived exosome (N-exo) was isolated from U-exo by immunoprecipitation. iTRAQ-based MALDI TOF MS/MS was used for proteomic analysis. The results showed that compared to WT, the levels of 61 and 92 proteins were increased in the J20 U-exo and N-exo, respectively. Gene ontology enrichment analysis demonstrated that the sphingolipid catabolic process, ceramide catabolic process, membrane lipid catabolic process, Aß clearance, and Aß metabolic process were highly enriched in U-exo and N-exo. Among these, Asah1 was shown to be the key protein in lipid metabolism, and clusterin, ApoE, neprilysin, and ACE were related to Aß metabolism and clearance. Furthermore, protein-protein interaction analysis identified four protein complexes where clusterin and ApoE participated as partner proteins. Thus, J20 U-exo and N-exo contain proteins related to lipid- and Aß-metabolism in the early stages of AD, providing a new insight into the underlying pathological mechanism of early AD.

Does overnight duty affect vascular endothelial function?

BACKGROUND: The reactive hyperemia index (RHI), which is obtained from the measurement of peripheral arterial tonometry (PAT), is highly associated with the percentage change in the end-diastolic arterial diameter (%flow-mediated dilatation) at reactive hyperemia. Low RHI is reported to be a mortality risk in patients with a high risk of cardiovascular (CV) disease. CV events are thought to be induced by physical and mental stress, including long-term fatigue and lack of sleep. However, the relationship between fatigue, lack of sleep, and endothelial function has not yet been established. METHODS: Healthy hospital workers (n = 13, 6 men and 7 women) with an average age of 31.6 years were assigned to this study after they provided written informed consent. During the study period, we conducted 72 measurements of reactive hyperemia-peripheral arterial tonometry (RH-PAT) in the morning before or after their duty. At each measurement of the RH-PAT, we recorded the participants' hours of sleep and evaluated their degree of fatigue using a visual analog scale (VAS). RESULTS: Although the VAS was significantly less (36 ± 16% and 64 ± 12%, p < 0.001) and the hours of sleep were longer (6.0 ± 1.1 h and 2.3 ± 1.0 h, p < 0.001) before duty compared to those after duty, the RHI was comparable between them (2.12 ± 0.53 vs. 1.97 ± 0.50, p = 0.21). The VAS score was significantly higher in participants with low RHI (< 1.67) than in those with normal RHI (≥ 2.07) (59 ± 13% and 46 ± 21%, respectively, p < 0.05). However, binary logistic regression showed no significant association between low RHI and the VAS when adjusted for systemic blood pressure (SBP) and heart rate variability (HRV). In a simple regression analysis, the RHI was significantly correlated with the VAS score but not with sleep duration. A multiple linear regression analysis also showed no significant association between the RHI and VAS scores after adjustment for SBP and HRV. CONCLUSIONS: Vascular endothelial function was not associated with overnight duty, hours of sleep, or degree of fatigue in healthy young adults. Since the RHI may be decreased in severe fatigue conditions through autonomic nerve activity, one should consider the physical and mental conditions of the examinee when evaluating the RH-PAT results.

Bone responsiveness to parathyroid hormone is negatively associated with parathyroid hormone-lowering drug use in patients undergoing hemodialysis: a cross-sectional study.

BACKGROUND: Parathyroid hormone (PTH) acts on bone to indirectly increase the number and activity of osteoclasts. Thus, PTH has a stimulatory effect on bone resorption and upregulates bone turnover. However, the responsiveness of bone to PTH varies widely among patients receiving dialysis. In fact, relative to the serum PTH level, the level of serum tartrate-resistant acid phosphatase-5b (TRACP-5b), a bone resorption marker derived from osteoclasts, varies as well. This study aimed to examine factors related to bone responsiveness to PTH in patients undergoing chronic hemodialysis (HD). METHODS: This study included patients receiving chronic HD in Kawasaki Municipal Tama Hospital (Kanagawa, Japan) and Yonaha Medical Clinic (Okinawa, Japan) and excluded patients who received HD for less than 6 months, those who received a combination of HD and peritoneal dialysis, and those who had cancer bone metastases or myeloma. The TRACP-5b/intact PTH (iPTH) ratio was created as an index of bone responsiveness to PTH, categorized into tertiles (low, medium, and high), and a cross-sectional study was conducted. P < 0.05 indicated statistically significant differences. RESULTS: One hundred and six patients were analyzed. Age (P = 0.010), body mass index (BMI) (P = 0.003), use of calcium-sensing receptor (CaSR) agonists (P = 0.008), use of vitamin D receptor activators (VDRAs) (P = 0.012), plasma iPTH level (P < 0.001), serum 1,25(OH)2D level (P = 0.003), and serum TRACP-5b level (P < 0.001) were significantly different among the three categories. In the single linear regression analysis, age (P = 0.016), corrected serum calcium level (P = 0.007), and ln [1,25(OH)2D] (P = 0.044) showed a significant positive correlation with ln [TRACP-5b/iPTH], whereas BMI (P = 0.026), use of CaSR agonists (P = 0.001), use of VDRAs (P = 0.009), and serum phosphorus level (P = 0.018) showed a significant negative correlation. Upon conducting multiple linear regression analysis incorporating significant variables in the single linear regression analysis, a significant negative correlation was observed between the TRACP-5b/iPTH ratio and intravenous administration of a CaSR agonist (etelcalcetide) and/or a VDRA (calcitriol or maxacalcitol) in all the adjusted models. CONCLUSIONS: Bone responsiveness to PTH is negatively correlated with the intravenous administration of a CaSR agonist and/or a VDRA in patients undergoing chronic HD.

Aggregation of Cystatin C Changes Its Inhibitory Functions on Protease Activities and Amyloid ß Fibril Formation.

Cystatin C (CST3) is an endogenous cysteine protease inhibitor, which is implicated in cerebral amyloid angiopathy (CAA). In CAA, CST3 is found to be aggregated. The purpose of this study is to investigate whether this aggregation could alter the activity of the protein relevant to the molecular pathology of CAA. A system of CST3 protein aggregation was established, and the aggregated protein was characterized. The results showed that CST3 aggregated both at 80 °C without agitation, and at 37 °C with agitation in a time-dependent manner. However, the levels of aggregation were high and appeared earlier at 80 °C. Dot-blot immunoassay for oligomers revealed that CST3 could make oligomeric aggregates at the 37 °C condition. Electron microscopy showed that CST3 could make short fibrillary aggregates at 37 °C. Cathepsin B activity assay demonstrated that aggregated CST3 inhibited the enzyme activity less efficiently at pH 5.5. At 7.4 pH, it lost the inhibitory properties almost completely. In addition, aggregated CST3 did not inhibit Aß1-40 fibril formation, rather, it slightly increased it. CST3 immunocytochemistry showed that the protein was positive both in monomeric and aggregated CST3-treated neuronal culture. However, His6 immunocytochemistry revealed that the internalization of exogenous recombinant CST3 by an astrocytoma cell culture was higher when the protein was aggregated compared to its monomeric form. Finally, MTT cell viability assay showed that the aggregated form of CST3 was more toxic than the monomeric form. Thus, our results suggest that aggregation may result in a loss-of-function phenotype of CST3, which is toxic and responsible for cellular degeneration.

Neighborhood environment and muscle mass and function among rural older adults: a 3-year longitudinal study.

BACKGROUND: Sarcopenia, resulting from loss of muscle mass and function, is highly prevalent in the ageing societies and is associated with risk of falls, frailty, loss of independence, and mortality. It is important to identify environmental risk factors, so that evidence-based interventions to prevent sarcopenia can be implemented at the population level. This study aimed to examine the potential effect of several objectively measured neighborhood environmental factors on longitudinal change of muscle mass and function among older adults living in rural Japanese towns where the population is ageing. METHODS: This study was based on data from the Shimane CoHRE Study conducted by the Center for Community-based Healthcare Research and Education (CoHRE) at Shimane University in 3 rural towns in the Shimane Prefecture, Japan. Subjects older than 60 years, who participated in an annual health examination in 2016 and any follow-up years until 2019, i.e., 4 possible time points in total, were included (n = 2526). The skeletal muscle mass index (SMI) and grip strength were assessed objectively for each year as a measure of muscle mass and function, respectively. Neighborhood environmental factors, i.e., hilliness, bus stop density, intersection density, residential density, and distance to a community center were measured by geographic information systems (GIS). Linear mixed models were applied to examine the potential effect of each neighborhood environmental factor on the change of SMI and grip strength over time. RESULTS: Males living far from community centers had a less pronounced decline in SMI compared to those living close to community centers. Females living in areas with higher residential density had a less pronounced decline in grip strength compared to those living in areas with lower residential density. CONCLUSIONS: Neighborhood environmental factors had limited effects on change of SMI and grip strength among rural older adults within the 3 years follow up. Further long-term follow up studies are necessary by also taking into account other modifiable neighborhood environmental factors.

Physical inactivity and vitamin D deficiency in hospitalized elderlies.

Serum levels of 25(OH)D, which is known to correlate with systemic nutritional status, is used as an indicator of vitamin D sufficiency in the body. We studied the 25(OH)D status and its background factors including activity of daily living (ADL) in the elderlies hospitalized at the regional core hospital. We also examined whether or not vitamin D deficiency affects ADL among them. This study included newly hospitalized patients aged 65 years or over at Ohchi hospital April to August in 2015. At the time of admission, serum 25(OH)D concentration was measured, and ADL, instrumental ADL (IADL), cognitive function, blood test, nursing care certification were investigated as background factors. Among 209 patients, 25(OH)D was sufficient (> 30 ng/mL) only 14 cases (7%), insufficient (20-30 ng/mL) in 43 cases (20%), and deficient (< 20 ng/mL) in 152 cases (73%). Multivariate analysis showed that low ADL (OR 0.99, 95% CI 0.97-0.99) and low IADL (OR 0.88, 95% CI 0.78-0.99) were independent predictors of 25(OH)D deficiency in two models incorporating ADL and IADL, respectively. Furthermore, low 25(OH)D level was significantly associated with low ADL (OR 0.95, 95% CI 0.91-0.99) and low IADL (OR 0.93, 95% CI 0.88-0.97) scores, suggesting that vitamin D deficiency may affect physical activities. Most hospitalized elderly patients in Japan were deficient for vitamin D. In addition, physical inactivity is strongly associated with vitamin D deficiency.

Height loss but not body composition is related to low back pain in community-dwelling elderlies: Shimane CoHRE study.

BACKGROUND: Low back pain (LBP) is a common complaint in the elderly Japanese population. Although previous studies showed that height loss was associated with LBP, it remains unclear whether LBP is associated with body composition. The objective of the present study was to investigate whether body composition and physical characteristics, including height loss, were associated with LBP. METHODS: The present study is retrospectively registered, and the participants were 2212 community-dwelling Japanese people aged over 60 years who participated in the Shimane CoHRE study in 2016. We investigated the presence of LBP, body composition parameters (muscle, fat, body weight, and bone mass), physical characteristics (body height and height loss), chronic diseases, history of fall, smoking, and drinking habits. We examined the relationships of body composition parameters and physical characteristics with point prevalence of LBP using multivariate logistic regression. RESULTS: The point prevalence of LBP was 43.2% in women and 39.5% in men. Logistic regression models showed that body height and body composition were not significantly associated with LBP; however, height loss was associated significantly with LBP in women and men (OR: 1.14, 95% CI: 1.08-1.20 and OR: 1.13, 95% CI: 1.06-1.21, respectively). Hypertension (OR: 1.32, 9 5% CI: 1.04-1.69) and chronic heart disease (OR: 1.57, 95% CI: 1.01-2.43) in women and history of fall (OR: 1.70, 95% CI: 1.13-2.56) and cerebrovascular disease (OR: 1.88, 95% CI: 1.05-3.34) in men were significantly associated with LBP. However, body composition was not associated with LBP in either gender. CONCLUSIONS: The present study demonstrated that height loss, but not body composition, was related to LBP in community-dwelling elderly people. To elucidate the cause of LBP, it is important to consider the relationship with height loss.

Evaluation of autonomic functions of patients with multiple system atrophy and Parkinson's disease by head-up tilt test.

The aim of this study was to evaluate the autonomic neural function in Parkinson's disease (PD) and multiple system atrophy (MSA) with head-up tilt test and spectral analysis of cardiovascular parameters. This study included 15 patients with MSA, 15 patients with PD, and 29 healthy control (HC) subjects. High frequency power of the RR interval (RR-HF), the ratio of low frequency power of RR interval to RR-HF (RR-LF/HF) and LF power of systolic BP were used to evaluate parasympathetic, cardiac sympathetic and vasomotor sympathetic functions, respectively. Both patients with PD and MSA showed orthostatic hypotension and lower parasympathetic function (RR-HF) at tilt position as compared to HC subjects. Cardiac sympathetic function (RR-LF/HF) was significantly high in patients with PD than MSA at supine position. RR-LF/HF tended to increase in MSA and HC, but decreased in PD by tilting. Consequently, the change of the ratio due to tilting (ΔRR-LF/HF) was significantly lower in patients with PD than in HC subjects. Further analysis showed that compared to mild stage of PD, RR-LF/HF at the supine position was significantly higher in advanced stage. By tilting, it was increased in mild stage and decreased in the advanced stage of PD, causing ΔRR-LF/HF to decrease significantly in the advanced stage. Thus, we demonstrated that spectral analysis of cardiovascular parameters is useful to identify sympathetic and parasympathetic disorders in MSA and PD. High cardiac sympathetic function at the supine position, and its reduction by tilting might be a characteristic feature of PD, especially in the advanced stage.

Development of the Japanese version of the general practice assessment questionnaire: measurement of patient experience and testing of data quality.

BACKGROUND: Physicians' interpersonal performance is critical in medical practice, especially primary care practice. The General Practice Assessment Questionnaire (GPAQ) was developed in the United Kingdom to evaluate the quality of primary care from the viewpoint of patients. This questionnaire highlights the evaluation of interpersonal skills and interactions between physicians and patients. Though several other tools also exist to evaluate primary care quality, the GPAQ has several distinctive evaluation items, covering receptionists, access to primary care, and enablement (patients' understanding of self-care and of their own health after consultation). Our purpose was to develop and validate a Japanese version of the GPAQ. METHODS: This cross-sectional study tested the validity and reliability of the Japanese version of the questionnaire. We translated the original GPAQ into Japanese and assessed its reliability and validity among patients aged ≥20 years at five rural primary care centres located in Shimane and Okayama prefectures, Japan. We also examined its internal reliability using Cronbach's alpha coefficient and construct validity-including item-scale correlations, item-other scale correlations, and inter-scale correlations. Moreover, we examined correlations between each score and overall satisfaction using Spearman's correlation coefficient for criterion-related validity. RESULTS: The translated version of the GPAQ was administered, and we received 252 responses (mean age: 68 ± 12.3 years, male: 42.9%); all data were analysed. The translated questionnaire showed good reliability and validity, with Cronbach's alphas ranging from 0.79-0.92 for all scales, and satisfactory item-scale, item-other scale, and inter-scale correlations. Correlations with overall satisfaction were strong (Spearman's correlation coefficients: 0.31-0.38) for all scales except 'continuity of care'. CONCLUSIONS: The Japanese version of the GPAQ was acceptable, reliable, and valid. This could be a useful instrument to evaluate key areas of primary care performance in Japan, particularly physicians' communication skills. Further work is required to evaluate its utility in urban areas.

[Fragility Fractures in Hemodialysis Patients. "Classical" osteoporosis in dialysis patients.]

Previous studies demonstrated that patients undergoing chronic dialysis therapy showed several times higher risks for hip fracture compared to those of healthy subjects. Their bone tissue would be vulnerable because of the bone loss and poor quality. In addition, volume and strength of the muscle are decreased and the ratio of sarcopenia or frailty is increased among these patients, accordingly leading to higher risks for falls and bone fractures. Considering the pathophysiology of bone fracture in dialysis patients, it is a matter of course that one wonders how effective recently developed medicine for"classical" osteoporosis is. However, evidence to guide us is currently lacking. Therefore, it is crucial for us to construct evidence by observational and interventional studies.

Vitamin D-mediated hypercalcemia in multicentric Castleman's disease.

Multicentric Castleman's disease (MCD) is a rare lymphoproliferative disorder, which represents various symptoms caused by the hyperproduction of interleukin-6 (IL-6). However, case studies of MCD accompanied by hypercalcemia have rarely been reported thus far. A 78-year-old male had generalized fatigue, and his laboratory data revealed elevated serum calcium (Ca) and 1,25-dihydroxyvitamin D [1,25(OH)2D] levels (11.5 mg/dl and 80 pg/ml, respectively), while the serum intact parathyroid hormone level was low (4 pg/ml). Computed tomography showed multicentric lymphadenopathy. The serum IL-6 level was elevated (20.7 pg/ml), and pathological examination of a supraclavicular lymph node specimen led us to diagnose MCD. Moreover, immunostaining analysis showed that vitamin D-activating enzyme 25-hydroxyvitamin D 1-alpha-hydroxylase was expressed in lymph node macrophages. Prednisolone treatment improved the hypercalcemia and decreased the levels of 1,25(OH)2D and IL-6. We first reported a case of vitamin D-mediated hypercalcemia in MCD.

Advanced Glycation End-Products Induce Apoptosis of Vascular Smooth Muscle Cells: A Mechanism for Vascular Calcification.

Vascular calcification, especially medial artery calcification, is associated with cardiovascular death in patients with diabetes mellitus and chronic kidney disease (CKD). To determine the underlying mechanism of vascular calcification, we have demonstrated in our previous report that advanced glycation end-products (AGEs) stimulated calcium deposition in vascular smooth muscle cells (VSMCs) through excessive oxidative stress and phenotypic transition into osteoblastic cells. Since AGEs can induce apoptosis, in this study we investigated its role on VSMC apoptosis, focusing mainly on the underlying mechanisms. A rat VSMC line (A7r5) was cultured, and treated with glycolaldehyde-derived AGE-bovine serum albumin (AGE3-BSA). Apoptotic cells were identified by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. To quantify apoptosis, an enzyme-linked immunosorbent assay (ELISA) for histone-complexed DNA fragments was employed. Real-time PCR was performed to determine the mRNA levels. Treatment of A7r5 cells with AGE3-BSA from 100 µg/mL concentration markedly increased apoptosis, which was suppressed by Nox inhibitors. AGE3-BSA significantly increased the mRNA expression of NAD(P)H oxidase components including Nox4 and p22(phox), and these findings were confirmed by protein levels using immunofluorescence. Dihydroethidisum assay showed that compared with cBSA, AGE3-BSA increased reactive oxygen species level in A7r5 cells. Furthermore, AGE3-induced apoptosis was significantly inhibited by siRNA-mediated knockdown of Nox4 or p22(phox). Double knockdown of Nox4 and p22(phox) showed a similar inhibitory effect on apoptosis as single gene silencing. Thus, our results demonstrated that NAD(P)H oxidase-derived oxidative stress are involved in AGEs-induced apoptosis of VSMCs. These findings might be important to understand the pathogenesis of vascular calcification in diabetes and CKD.

[Clinical evaluation for abnormalities of bone and mineral metabolism in ESKD].

In patients with end-stage kidney disease(ESKD), bone disorders are characterized by cortical porosity and by abnormal turnover of bone metabolism:adynamic(low turnover)bone disease and high turnover bone due to various degrees of secondary hyperparathyroidism. Abnormalities of bone metabolism are generally assessed by interview, X-ray, bone mineral density(BMD), serum phosphorus, calcium, and parathyroid hormone levels, and bone metabolic markers. Recent clinical studies have demonstrated that high turnover bone representing elevated bone metabolic markers and low BMD are independent risks of bone fractures as well as mortality among this population. Treatment of bone disorders in ESKD patients should be aiming at the normalization of mineral metabolism and the maintenance and/or improvement of BMD.

Active vitamin D possesses beneficial effects on the interaction between muscle and bone.

Vitamin D deficiency and advanced glycation end products (AGEs) are suggested to be involved in the pathogenesis of osteoporosis and sarcopenia. However, the effects of vitamin D and AGEs on myogenesis and the interaction between muscle and bone remains still unclear. We previously showed that osteoglycin (OGN) is secreted from myoblasts and stimulates osteoblastic differentiation, suggesting that it plays important roles in the interaction between muscle and bone. The aim of this study is thus to examine the effects of vitamin D and AGEs on myoblastic differentiation of C2C12 cells and osteoblastic differentiation of osteoblastic MC3T3-E1 cells through OGN expression. 1α,25-dihydroxyvitamin D3 (1,25D) and eldecalcitol, an active vitamin D analog, induced the expression of MyoD, myogenin and OGN, and these effects were abolished by vitamin D receptor (VDR) suppression by siRNA in C2C12 cells. Moreover, conditioned medium from 1,25D-pretreated C2C12 cells stimulated the expression of type 1 collagen and alkaline phosphatase in MC3T3-E1 cells, compared to control medium from 1,25D-untreated C2C12 cells. In contrast, conditioned medium from VDR-suppressed and 1,25D-pretreated C2C12 cells showed no effects. AGE2 and AGE3 suppressed the expression of MyoD, myogenin and OGN in C2C12 cells. Moreover, 1,25D blunted the AGEs' effects. In conclusion, these findings showed for the first time that active vitamin D plays important roles in myogenesis and muscle-induced osteoblastogenesis through OGN expression. Active vitamin D treatment may rescue the AGEs-induced sarcopenia as well as - suppressed osteoblastic differentiation via OGN expression in myoblasts.

Close relationship between serum hyaluronan levels and vascular function in patients with type 2 diabetes.

OBJECTIVE: To clarify the relationship between serum hyaluronan levels and vascular function in type 2 diabetic patients. METHODS: A cross-sectional cohort study. RESULTS: In multivariate regression analysis, endothelium-dependent flow-mediated dilation was associated with age and duration of diabetes, but not with serum hyaluronan level, while endothelium-independent nitroglycerine-mediated dilation (NMD) was only associated with serum hyaluronan level (standardized estimate = -0.401, p = 0.003). NMD in the lowest tertile of hyaluronan level was significantly higher than the other tertiles (15.9% versus 12.5% and 10.4%, p = 0.047 and p = 0.002, respectively). CONCLUSIONS: Serum hyaluronan level may be useful as a surrogate marker for early changes in the vascular function, which often occurs in patients with diabetes mellitus.

Effects of uremic toxin p-cresol on proliferation, apoptosis, differentiation, and glucose uptake in 3T3-L1 cells.

Malnutrition is a common feature seen in chronic dialysis patients, and the survival rate of obese patients receiving such treatment is higher than that of lean patients. Irrespective of obesity or diabetes, dialysis patients commonly have insulin resistance, and the leading cause of death is cardiovascular (CV) disease. It has been reported that the concentration of p-cresol, a uremic toxin, is highly associated with CV events. As uremic toxin levels are high in dialysis patients, they may be involved in the pathogenesis of insulin resistance and CV disease in this population. However, little is known so far. Thus, we focused on this uremic toxin to examine its effects on adipocytes and their precursors. 3T3-L1 cells, a mouse preadipocyte cell line, were cultured until 90% confluency. The cells were then differentiated with 500 µM 3-isobutyl-methylxanthine, 250 nM dexamethasone, and 10 µg/mL insulin. Cell proliferation was evaluated by cell counting and bromodeoxyuridine (Brd-U) incorporation assay. Glucose uptake was estimated using radiolabeled 2-deoxyglucose. The range of concentrations of p-cresol used in the experiments was from 2 to 200 µM. The investigation of cell proliferation by cell counting revealed that, compared with control, 3T3-L1 cells treated with 100 and 200 µM p-cresol were significantly decreased in number at day 3 and day 7 of culture. The Brd-U incorporation assay also demonstrated similar inhibitory effects on cell proliferation, suggesting that p-cresol affected the normal cell cycle. Oil Red O staining at day 7 showed that the number of mature adipocytes was decreased by treatment with 200 µM p-cresol. Consistent with that finding, the number of apoptotic cells at day 7 was increased by treatment with 100 and 200 µM p-cresol. Peroxisome proliferator-activated receptor γ (PPARγ) mRNA expression increased time-dependently during the differentiation process of 3T3-L1 cells. p-Cresol dose-dependently decreased differentiation-induced mRNA expression of PPARγ. Uptake of 3H-labeled 2-deoxyglucose was markedly decreased by 200 µM p-cresol in the presence or in the absence of insulin, mainly because of the decreased number of mature adipocytes. High concentrations of p-cresol disturbed the cell cycle, induced apoptosis, inhibited the differentiation of preadipocytes into mature adipocytes, and decreased glucose uptake at baseline and after insulin stimulation. These findings indicate that accumulated p-cresol may induce reduction in adipose tissue, insulin resistance, and malnutrition, eventually leading to poor outcomes in chronic dialysis patients.

[Daily subcutaneous injection of teriparatide : the progress and current issues].

Daily subcutaneous injection of teriparatide, which consists of 34 amino acids of N-terminal of parathyroid hormone, has been investigated as a therapy for osteoporosis. It has been used since 2010 in Japan. Since teriparatide markedly stimulates bone formation, its daily injection increases bone volume mainly at the cancellous bone and significantly reduces vertebral and non-vertebral fracture risk. Because of the limitation (2 years) of the use in the life span, sequential treatment following teriparatide is needed. When combined with an antiresorptive agent, teriparatide showed additive increase in bone mineral density. However, it remains uncertain which agent is the best for the combination and what schedule is the most effective. Since teriparatide reduces back pain and stimulates bone repair, it is suitable for patients with back pain or with severe osteoporosis.