C-terminal Propeptide Research Articles

A prospective randomized controlled trial of bone metabolism in patients with charcot foot

BACKGROUND: Diabetic neuroosteoarthropathy (DNOAP, Charcots foot) - is a progressive destructive inflammatory disease of the osteoarticular apparatus of the foot, untimely and inadequate treatment of which can lead to the formation of gross deformities. More often, DNOAP is unilateral, bilateral lesion is relatively rare. It is not always possible to trace the relationship between the debut of DNOAP with trauma and chronic hyperglycemia. There is data demonstrating the role of individual pro-inflammatory factors in the pathogenesis of DNOAP, however, studies combining the evaluation of various metabolic markers of Charcots foot formation are currently extremely poor.
 AIM: To evaluate the hormonal and metabolic markers of bone formation and resorption in patients with DNOAP and without this diabetic complication.
 METHODS: A prospective, controlled trial included 70 patients with type 2 diabetes mellitus (37 men and 43 women) who formed 2 groups: group 1 included patients with DNOAP, group 2 was formed by patients with diabetes without foot skeleton damage. All patients underwent a study of 1,25-OH-vitamin D, sclerostin, pro-MMP-1, C-terminal propeptide type 1 collagen (PICP), type 1 collagen, osteocalcin, PTH, 25-OH-vitamin D, beta-cross-slaps.
 RESULTS: The results of the studies confirmed the presence of vitamin D deficiency in all patients with diabetes mellitus included in the study, revealed the absence of statistically significant differences between the groups in the values of sclerostin, pro-MMP-1; 25-OH-vitamin D, type I collagen, and osteocalcin (p 0.05). However, significant differences were found in the 1.25-OH vitamin D levels: patients with DNOAP presented the lower rates of 1,25-OH-vitamin D in comparison to control group (p 0.05). Beta-cross and PICP levels were significantly higher in DNOAP patients as well (p 0.05). Those findings show the more severe collagen degradation in patients with DNOAP and can be the genetically predisposed cause of DNOAP development. Though further studies are needed.
 CONCLUSION: In patients with DNOAP a decrease in 1,25-OH-vitamin D levels was found, as well as the alteration of the synthesis and destruction of collagen (beta-cross-slaps and PICP) compared to patients with diabetes mellitus without osteoarticular disorders.

A prospective randomized controlled trial of bone metabolism in patients with charcot foot

BACKGROUND: Diabetic neuroosteoarthropathy (DNOAP, Charcot’s foot) - is a progressive destructive inflammatory disease of the osteoarticular apparatus of the foot, untimely and inadequate treatment of which can lead to the formation of gross deformities. More often, DNOAP is unilateral, bilateral lesion is relatively rare. It is not always possible to trace the relationship between the debut of DNOAP with trauma and chronic hyperglycemia. There is data demonstrating the role of individual pro-inflammatory factors in the pathogenesis of DNOAP, however, studies combining the evaluation of various metabolic markers of Charcot’s foot formation are currently extremely poor. AIM: To evaluate the hormonal and metabolic markers of bone formation and resorption in patients with DNOAP and without this diabetic complication. METHODS: A prospective, controlled trial included 70 patients with type 2 diabetes mellitus (37 men and 43 women) who formed 2 groups: group 1 included patients with DNOAP, group 2 was formed by patients with diabetes without foot skeleton damage. All patients underwent a study of 1,25-OH-vitamin D, sclerostin, pro-MMP-1, C-terminal propeptide type 1 collagen (PICP), type 1 collagen, osteocalcin, PTH, 25-OH-vitamin D, beta-cross-slaps. RESULTS: The results of the studies confirmed the presence of vitamin D deficiency in all patients with diabetes mellitus included in the study, revealed the absence of statistically significant differences between the groups in the values of sclerostin, pro-MMP-1; 25-OH-vitamin D, type I collagen, and osteocalcin (p > 0.05). However, significant differences were found in the 1.25-OH vitamin D levels: patients with DNOAP presented the lower rates of 1,25-OH-vitamin D in comparison to control group (p <0.05). Beta-cross and PICP levels were significantly higher in DNOAP patients as well (p <0.05). Those findings show the more severe collagen degradation in patients with DNOAP and can be the genetically predisposed cause of DNOAP development. Though further studies are needed. CONCLUSION: In patients with DNOAP a decrease in 1,25-OH-vitamin D levels was found, as well as the alteration of the synthesis and destruction of collagen (beta-cross-slaps and PICP) compared to patients with diabetes mellitus without osteoarticular disorders.

Fibrillin-1 and fibrillin-1-derived asprosin in adipose tissue function and metabolic disorders.

The extracellular matrix microenvironment of adipose tissue is of critical importance for the differentiation, remodeling and function of adipocytes. Fibrillin-1 is one of the main components of microfibrils and a key player in this process. Furin processing of profibrillin-1 results in mature fibrillin-1 and releases the C-terminal propeptide as a circulating hunger hormone, asprosin. Mutations in the fibrillin-1 gene lead to adipose tissue dysfunction and causes Marfan syndrome, marfanoid progeroid lipodystrophy syndrome, and neonatal progeroid syndrome. Increased TGF-β signaling, altered mechanical properties and impaired adipogenesis are potential causes of adipose tissue dysfunction, mediated through deficient microfibrils. Circulating asprosin on the other hand is secreted primarily by white adipose tissue under fasting conditions and in obesity. It increases hepatic glucose production and drives insulin secretion and appetite stimulation through inter-organ cross talk. This review discusses the metabolic consequences of fibrillin-1 and fibrillin-1-derived asprosin in pathological conditions. Understanding the dynamic role of fibrillin-1 in the adipose tissue milieu and of circulating asprosin in the body can provide novel mechanistic insights into how fibrillin-1 may contribute to metabolic syndrome. This could lead to new management regimens of patients with metabolic disease.

In-hospital changes of echocardiographic parameters and their relationship with the procollagen I C-terminal propeptide in patients with myocardial infarction and preserved left ventricle systolic function

Aim. To study the changes of echocardiographic parameters and their relationship with the procollagen I C-terminal propeptide (PICP) during hospitalization of patients with ST-segment elevation myocardial infarction (STEMI) and preserved left ventricular (LV) systolic function.Material and methods. A total of 120 (100%) patients hospitalized with STEMI were examined. Upon admission, all patients underwent standard examinations to verify myocardial infarction (MI), including coronary angiography and, if necessary, coronary stent implantation. The mean values of LV ejection fraction (LVEF) were 40-49% in 3 patients (2,5%), &lt;40% — in 31 patients (26%), LVEF was. We also analyzed patients with LVEF ≥50%, n=86 (71,6%); mean age was 57,8 years. During the hospitalization, all patients received standard therapy; on the 1st and 12th day of MI, the PICP levels in venous blood serum was determined by enzyme-linked immunosorbent assay. In order to compare PICP values, a control group of healthy volunteers n=20 (100%) was formed, which were comparable by gender and age. In this group, the concentration of PICP was 179,2 [163.5; 194.9] ng/ml.Results. By the 12th day, a significant decrease in the following parameters of the transmitral flow was revealed: DT (p=0,049), dE (0,012), Em (0,029), Em/ Am (p=0,000), Em/PICP (p=0,001). This indicates diastolic function deterioration. At the same time, by the end of hospitalization, systolic function deterioration was recorded in 15,1% of cases. Initially, a higher PICP on the 1st day relative to the control group tended to decrease the concentration by the 12th day, but the differences did not reach statistical significance (p=0,466). Correlation analysis showed a relationship between PICP and echocardiography (Tei index, p=0,026, and mitral annulus velocity, p=0,049).Conclusion. At the hospital stage of treatment of patients with STEMI and preserved LVEF, a negative changes of echocardiography parameters characterizing diastolic dysfunction was revealed. Positive correlation was established between the concentration of PICP with mitral annulus velocity and the Tei index, indicating an association between the myocardial fibrosis and diastolic dysfunction.

Procollagen propeptides and visceral obesity index in patients with myocardial infarction with preserved emission faction and various metabolic phenotype

Purpose. To identify the peculiarities of the dynamics of fibrosis markers of C-terminal procollagen propeptide type I (PICP) and N-terminal collagen propeptide type III (PIIINP) in patients with ST segment elevation myocardial infarction (STEMI) and preserved myocardial contractility.Material and methods. 86 patients with STEMI and preserved left ventricular ejection fraction were examined. In addition to the standard laboratory and instrumental examinations, all the patients underwent the estimation of the concentrations of C-terminal procollagen propeptide type I (PICP) and N-terminal collagen propeptide type III (PIIINP) by enzyme-linked immunoassay using BCM Diagnostics laboratory kits (USA) on the 1st and the 12th days of disease and 1 year later.Results. The concentration of PICP was significantly reduced in all groups during the entire observation period. Significant correlations were found between PICP and visceral obesity index, age and left ventricular ejection fraction. A relationship was found between PIIINP and an increased visceral obesity index.

Low fibrosis biomarker levels predict cardiac resynchronization therapy response

Cardiac fibrosis is associated with heart failure and poor prognosis. Fibrosis biomarkers have been poorly evaluated as a tool to predict cardiac resynchronization therapy (CRT) response generating conflicting results. The present study assessed the predictive value of cardiac fibrosis biomarkers on CRT response. Patients underwent clinical examination, echocardiography and blood fibrosis biomarker evaluation prior to CRT implantation. At six months, a positive response to CRT was defined by a composite endpoint of no death or hospitalization for heart failure, and presence of left ventricular (LV) reverse remodeling (decrease in LV end-systolic volume ≥ 15%). Sixty patients were included in a multicenter study. At 6 months, 38 were positive responders to CRT and reached the response criteria (63%). Compared to non-responders, CRT responders displayed lower concentration levels of the fibrosis biomarkers procollagen type I C-terminal propeptide [PICP 135[99–166] ng/ml vs. 179[142–226] ng/ml, ( P = 0.001)] and procollagen type III N-terminal propeptide [PIIINP 5.50[3.66–8.96] ng/ml vs. 8.01[5.01–11.86]ng/ml, ( P = 0.014)] at baseline. In multivariate analysis, a PICP ≤ 163 ng/ml was associated with a positive CRT response [OR = 7.8(1.3–46.7), P = 0.023] independently of the presence of LBBB, QRS duration, LV lead position or non-ischemic cardiomyopathy. Altogether, the present findings show that a lower degree of cardiac fibrosis is associated with a positive response after CRT implantation. PICP evaluation before CRT implantation could help improve patient selection.

P5303Relationship of the dynamics of serum collagen and epicardial adipose tissue in patients with coronary heart disease and visceral obesity

Abstract Purpose Study of the effect of epicardial adipose tissue and in serum collagen in patients with myocardial infarction depending on the presence of visceral obesity. Methods 88 patients with CVD were assessed and divided into two groups based on the presence of visceral obesity (VO). Magnetic resonance imaging (MRI) was used to determine the area of the visceral (VAT) and subcutaneous adipose tissue (SAT) of the abdominal region, the thickness of epicardial adipose tissue, and the percentage of myocardial cardiac fibrosis a year after MI. VO was verified when the area of VAT &gt;130 cm2. We investigated changes in serum collagen: collagen protein type I (COL-1), N-terminal propeptide of procollagen type III (PIIINP) and C-terminal propeptide of procollagen type I (PICP). All study was carried out in compliance with the Helsinki Declaration, and its protocol was approved by the Ethical Committee of Research Institute. Statistical analysis was performed using Statistica 10.0. All patients gave written informed consent to participate in the study. Results With VO, the thickness of the left ventricular epicardial tissue (EATLv) was 1.75 times greater, and that of the right ventricle (EATrv), 1.43 times more than in patients without VO. In the group of patients with VO, the presence of a direct correlation was established between the magnitude of the area of VAT and EATLv (r=0.26, p=0.02), EATrv (r=0.26, p=0.01). the results indicate that myocardial damage on the background of an acute MI is characterized by higher concentrations of COL-1 (29065 pg/ml), PICP (638 ng/ml) and PIIINP (31431 pg/ml), in the presence of VO during the hospital period of MI, and exceeded the figures of patients without VO 2.15, 1.07 and 1.19 times, respectively. One year after MI, the COL 1 level in both groups decreased compared with the acute MI period (1.68 times in patients without VO and 2.75 times in patients with VO), it still remained higher in patients with VO in 1,4 times higher. And the level of PICP was not significantly different on the first day of MI and a year after suffering MI in the studied groups. PIIINP decreased only in the group of patients without VO. The data of the correlation analysis showed that EATLv was in direct connection with the level of serum collagen in patients with VO: EATLv - COL-1 (1 day (r=0.73; p=0.01), 1 year (r=−0, 84; p=0.00); EATLv - PICP (1 day (r=0.63; p=0.01), 1 year (r=0.57; p=0.03) and EATLv - PIIINP (1 day (r=0.61; p=0.03), 1 year (r=0.31; p=0.01). Conclusions Thus, the presence of VO in patients with MI is associated with higher concentrations of COL 1, PICP, PIIINP, both in the acute period of MI, and one year after a coronary catastrophe. The thickness of EAT is directly dependent on the degree of VO, and the concentration of COL-1, PICP and PIIINP on the value of EATLv.

Virgicin, a novel lanthipeptide from Virgibacillus sp. strain AK90 exhibits inhibitory activity against Gram-positive bacteria.

There is a significant increase in the discovery of new antimicrobial compounds in recent past to combat drug resistant pathogens. Members of the genus Bacillus and related genera have been screened extensively due to their ability to produce wide range of antimicrobial compounds. In this study, we have isolated and characterized a new antimicrobial peptide from a marine bacterium identified as Virgibacillus species. The low molecular mass and stability of the antimicrobial substance pointed towards the bacteriocinogenic nature of the compound. The RAST analysis of genome sequence showed presence of a putative bacteriocin biosynthetic cluster containing genes necessary for synthesis of a lanthipeptide. Translated amino acid sequence of mature C-terminal propeptide showed identity with salivaricin A (52.2%) and lacticin A (33.3%). Accordingly, the mass (2417Da) obtained by MALDI analysis was in agreement with posttranslational modifications of the leader peptide to yield three methyl lanthionine rings and a disulfide bond between two free cysteine residues. The lanthipeptide was named as virgicin, which selectively inhibited the growth of Gram-positive bacteria and biofilm formation by Enterococcus faecalis. Inhibition of biofilm formation by E. faecalis was also observed in in vitro model experiments using hydroxyapatite discs. Thus, virgicin appears to be a promising new bacteriocin to control oral biofilm formation by selective pathogens.

Compound phenotype of osteogenesis imperfecta and Ehlers-Danlos syndrome caused by combined mutations in COL1A1 and COL5A1.

Osteogenesis imperfecta (OI) is an inherited connective tissue disorder with a broad clinical spectrum that can overlap with Ehlers–Danlos syndrome (EDS). To date, patients with both OI and EDS have rarely been reported. In the present study, we investigated a family with four members, one healthy individual, one displaying OI only, and two displaying the compound phenotype of OI and EDS, and identified the pathogenic mutations. Whole exome sequencing was applied to the proband and her brother. To verify that the mutations were responsible for the pathogenesis, conventional Sanger sequencing was performed for all members of the family. We identified a known COL1A1 (encoding collagen type I α 1 chain) mutation (c.2010delT, p.Gly671Alafs*95) in all three patients (the proband, her brother, and her mother) in this family, but also a novel heterozygous COL5A1 (encoding collagen type V α 1 chain) mutation (c.5335A>G, p.N1779D) in the region encoding the C-terminal propeptide domain in the proband and her mother, who both had the compound phenotype of OI and EDS. The results of the present study suggested that the proband and her mother presented with the compound OI–EDS phenotype caused by pathogenic mutations in COL5A1 and COL1A1.

Differential cleavage of lysyl oxidase by the metalloproteinases BMP1 and ADAMTS2/14 regulates collagen binding through a tyrosine sulfate domain

Collagens are the main structural component of the extracellular matrix and provide biomechanical properties to connective tissues. A critical step in collagen fibril formation is the proteolytic removal of N- and C-terminal propeptides from procollagens by metalloproteinases of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) and BMP1 (bone morphogenetic protein 1)/Tolloid-like families, respectively. BMP1 also cleaves and activates the lysyl oxidase (LOX) precursor, the enzyme catalyzing the initial step in the formation of covalent collagen cross-links, an essential process for fibril stabilization. In this study, using murine skin fibroblasts and HEK293 cells, along with immunoprecipitation, LOX enzymatic activity, solid-phase binding assays, and proteomics analyses, we report that the LOX precursor is proteolytically processed by the procollagen N-proteinases ADAMTS2 and ADAMTS14 between Asp-218 and Tyr-219, 50 amino acids downstream of the BMP1 cleavage site. We noted that the LOX sequence between the BMP1- and ADAMTS-processing sites contains several conserved tyrosine residues, of which some are post-translationally modified by tyrosine O-sulfation and contribute to binding to collagen. Taken together, these findings unravel an additional level of regulation in the formation of collagen fibrils. They point to a mechanism that controls the binding of LOX to collagen and is based on differential BMP1- and ADAMTS2/14-mediated cleavage of a tyrosine-sulfated domain.

THE DYNAMICS OF MARKERS OF FIBROSIS WITH THE FEATURES OF METABOLIC PHENOTYPES IN PATIENTS WITH MYOCARDIAL INFARCTION

The features of the dynamics of serum markers of fibrosis, myocardial remodeling and progression of chronic insufficiency: C-terminal propeptide procollagen type I (PICP) and N-terminal propeptide procollagen type III (PIIINP) in patients with ST-segment elevation myocardial infarction were evaluated taking into account the peculiarities of the metabolic phenotype of patients. The study included 83 patients with left ventricular ejection fraction ≥50% of 120 patients admitted to the hospital with a diagnosis of ST-segment elevation myocardial infarction. Depending on the metabolic phenotype, the patients were divided into two groups: a group of 23 patients with normal body weight and a group of 60 patients with overweight and obesity of varying severity. The results indicate the relationship of serum markers of fibrosis of the myocardium with echocardiogram indicators, and myocardial remodeling in patients with myocardial infarction with ST-segment elevation. Isolation of patients with normal weight showed a general tendency to reduce the concentration of fibrosis markers regardless of the duration of the disease. The reverse trend allowed us to observe the selection of a group of patients with overweight or obesity. The obtained significant correlation between markers of myocardial fibrosis, data, echocardiogram, and anamnesis.

Elevated serum levels of procollagen C-proteinase enhancer-1 in patients with chronic kidney disease is associated with a declining glomerular filtration rate.

Procollagen C-proteinase enhancer-1 (PCPE-1) is a 55 kDa glycoprotein, which increases the activity of procollagen C-proteinases that break down C-terminal propeptides. Studies have shown that PCPE-1 is involved in the fibrotic process that occurs in various tissues and organs. Our review of the literature revealed no data concerning the relation between PCPE-1 and chronic kidney disease (CKD). The purpose of this study was to determine PCPE-1 levels in CKD. One hundred thirty-one CKD patients and 34 healthy controls were included in our study. Demographic data were recorded, and routine biochemical tests were performed. Blood specimens were collected for PCPE-1 investigation. Demographic data, biochemical test results and PCPE-1 levels were compared between the control and patient groups. Parameters affecting PCPE-1 levels in our patient group were assessed. Procollagen C-proteinase enhancer-1 levels were significantly higher in our patient group compared to the control group. Parameters affecting PCPE-1 elevation in the patient group were identified as systolic blood pressure, blood urea nitrogen, phosphorus, haemoglobin, intact parathormone levels, glomerular filtration rate and body mass index. We determined high PCPE-1 levels in CKD patients. PCPE-1 levels being negatively correlated with glomerular filtration rate suggests that PCPE-1 may be associated with progression in CKD patients.

Agonist-induced activation of the S1P receptor 2 constitutes a novel osteoanabolic therapy for the treatment of osteoporosis in mice.

Osteoporosis is a worldwide epidemic but pharmacological agents to stimulate new bone formation are scarce. We have shown that increasing tissue levels of sphingosine-1-phosphate (S1P) by blocking its degradation by the S1P lyase has pronounced osteoanabolic effect in mouse osteoporosis models by stimulating osteoblast differentiation through the S1P receptor 2 (S1P2). However, S1P lyase inhibitors have side effects complicating potential clinical use. Here, we tested whether direct S1P2 engagement by the S1P2 agonist CYM5520 exerted osteoanabolic potential in estrogen deficiency-induced osteopenia in mice. We compared its efficacy to LX2931, a novel S1P lyase inhibitor currently tested in rheumatoid arthritis. CYM5520, LX2931 or vehicle were administered to ovariectomized mice for 6 weeks beginning 5 weeks after ovariectomy, Bone mass, cellular composition and mechanical strength were assessed by microCT, histomorphometry and three point bending tests. Plasma markers of bone metabolism were analyzed by ELISA. Therapeutic treatment with CYM5520 and LX2931 clearly increased long bone and vertebral bone mass to impressive 3-5 fold over vehicle in osteopenic ovariectomized mice. As expected, lymphopenia was a side effect of LX2931, whereas none occurred with CYM5520. Consistent with an osteoanabolic effect, CYM5520 increased osteoblast number, osteoid surface and alkaline phosphatase area 2-3 fold over vehicle. Plasma concentrations of the osteoanabolic marker procollagen I C-terminal propeptide were also elevated by CYM5520 and LX2931. LX2931 but not yet CYM5520 increased cortical thickness and mechanical strength without affecting mineral density. Treatment with a pharmacological S1P2 agonist corrected ovariectomy-induced osteopenia in mice by inducing new bone formation thus constituting a novel osteoanabolic approach to osteoporosis.

Relations between markers of cardiac remodelling and left ventricular collagen in an isoproterenol-induced heart damage model.

There is a great urgency of detecting and monitoring myocardial fibrosis in clinical practice with the aim to improve and personalize therapy against cardiac remodelling. Hence, the aim of this study was to describe alterations in and show potential correlations between the structural characteristics and the molecular and biochemical markers of cardiac remodelling on a model of isoproterenol-induced heart failure. Two groups of 3-month-old male Wistar rats (n = 8 per group) were sacrificed after four weeks of treatment: control (placebo), ISO (5 mg/kg/day intraperitoneally). Chronic ISO treatment led to heart failure (HF) characterized by significant reduction of systolic blood pressure (SBP) accompanied by an increase in left ventricular weight (LVW) along with increased collagen content in the LV. The collagen content correlated negatively with SBP (R = -0.776, P < 0.001) and positively with LVW (R = 0.796, P < 0.001), with Col1a1 (0.83; P < 0.001) and Acta2 (0.73; P < 0.01). Moreover, the mRNA expression of fibrotic remodelling indicator, i.e. TGF-β1 tended to increase, while the level of fibrinolysis markers (MCP-1, TIMP-2, MMP) were unchanged. The plasma markers of collagen, procollagen I C-terminal propeptide (PICP) was 37.34 ± 7.10 pg/mL in control and was reduced by 42% (P < 0.05) in the ISO group and procollagen III N-terminal propeptide (PIIINP) was 1216.7 ± 191.0 pg/mL in control and was decreased by 66% (P < 0.05) in the ISO group. Surprisingly, there was no positive correlation between plasma markers of collagen, i.e. PICP and PIIINP and collagen content or molecular markers of collagen. However, both PICP and PIIINP correlated with BW (R = 0.712, resp. 0.803, P < 0.001), which was significantly reduced (by 25%, P < 0.05) in the ISO group. In conclusion, we assume that the collagen content of the left ventricle does not need unavoidably correlate with plasma markers of collagen, which might be affected by confounding factors in heart failure, such as loss of body weight, presumably associated with a catabolic condition.

Low fibrosis biomarker levels predict cardiac resynchronization therapy response

Cardiac fibrosis is associated with heart failure and poor prognosis. Fibrosis biomarkers have been poorly evaluated as a tool to predict cardiac resynchronization therapy (CRT) response generating conflicting results. The present study assessed the predictive value of cardiac fibrosis biomarkers on CRT response. Patients underwent clinical examination, echocardiography and blood fibrosis biomarker evaluation prior to CRT implantation. At six months, a positive response to CRT was defined by a composite endpoint of no death or hospitalization for heart failure, and presence of left ventricular (LV) reverse remodeling (decrease in LV end-systolic volume ≥15%). Sixty patients were included in a multicenter study. At 6 months, 38 were positive responders to CRT and reached the response criteria (63%). Compared to non-responders, CRT responders displayed lower concentration levels of the fibrosis biomarkers procollagen type I C-terminal propeptide [PICP 135[99–166] ng/ml vs. 179[142–226]ng/ml, p = 0.001)] and procollagen type III N-terminal propeptide [PIIINP 5.50[3.66–8.96] ng/ml vs. 8.01[5.01–11.86]ng/ml, p = 0.014)] at baseline. In multivariate analysis, a PICP ≤ 163 ng/ml was associated with a positive CRT response [OR = 7.8(1.3–46.7), p = 0.023] independently of the presence of LBBB, QRS duration, LV lead position or non-ischemic cardiomyopathy. Altogether, the present findings show that a lower degree of cardiac fibrosis is associated with a positive response after CRT implantation. PICP evaluation before CRT implantation could help improve patient selection.

SUN-538 Osteogenic Markers in Postmenopausal Diabetics Respond to Higher Mechanical Loading during Exercise after Rather Than before the Meals

Structural integrity of bones is supported by mechanical loading, energy intake, and sex hormones. It is unclear why postmenopausal (PM) diabetics experience more bone breaks despite higher body weight and positive energy balance than non-diabetics. We hypothesized that greater bone fragility in PM diabetics may result from peripheral insulin resistance and reduced nutrient access to the bone. We engaged 15 diabetic women, age 57.7y, BMI 27.2 kg/m2, in two of five day-long experiments : SED (no exercise), UBM and UAM (40 min of uphill treadmill exercise, respectively one h before, or one h after eating two daily isocaloric meals at 10 and 17 h and containing 50% carbohydrate, 15% protein, and 25% fat), and DBM and DAM (downhill exercise at -6o slope with meals and exercise timed the same way). Markers of bone formation osteocalcin (OCN) and CICP (c-terminal propeptide of type I collagen) and of resorption, CTX (c-terminal telopeptide of type I collagen), anabolic growth hormone and catabolic cortisol were measured hourly in the serum. Glucose and insulin were measured to assess insulin resistance by the homeostatic HOMA-IR method from 7-h postprandial (PP) insulin and glucose areas under the curve (AUCs).Peak ground-reaction forces (GRFs) were monitored with Novel Pedar mechanosensitive shoe insoles, and physical effort was assessed as percent of VO2max with a metabolic cart. During uphill trials, mean effort was 75.2% , and GRFs were 780.7 N. During downhill trials, the corresponding values were 47.9% of VO2max and 1104.8 N (both >0.05). A similar CTX decline in all 5 trials after the 10h meal was larger than after the 17 h meal (7h negative PP AUCs: 1.52 vs 1.37 ng/ml*h, respectively) and coincided with PP insulin AUCs. CICP rise in DAM trial was 44% greater than in DBM trial after 10h meal (AUCs, 685.9 vs 384.1 ng/ml*h, respectively) and produced a 40 percent greater osteogenic CICP/CTX ratio after 10h meal in the in the DAM than DBM trial. No group difference was seen in brief postprandial serum glucose rises, while PP insulin was highest in UBM and SED trials and low in the two downhill and UAM trials. HOMA-IR in the two downhill trials (355.6) was reduced to 47% of that in two uphill trials (759.1) and to 62% of the SED trial (571.4). Circulating OCN and hormones showed no clear relationship to either the loading or meal-exercise timing patterns. We conclude that In PM diabetics, downhill (as opposed to uphill) exercise after a meal conveys a clear benefit in stimulating a bone- forming CICP, more so after the 10h than the 17 h meal. Meal eating, independently of exercise, lowers the bone resorption marker CTX. In diabetic PM women, Increased GRFs of downhill exercise reduce HOMA-IR insulin resistance to high-carbohydrate meals more than uphill exercise or SED control. Postprandial downhill exercise has the highest osteogenic potential.

A dual-label time-resolved fluorescence immunoassay for screening of osteoporosis based on simultaneous detection of C-terminal telopeptide (β-CTX) and aminoterminal propeptide (P1NP) of type I procollagen

Osteoporosis is a disease where increased bone weakness increases the risk of a broken bone. Until a broken bone occurs, there are typically no symptoms. Osteoporosis affects more than 75 million people in the United States, Europe and Japan. The diagnosis of osteoporosis is primarily determined by measuring bone mineral density using dual-energy X-ray absorptiometry, but for men under 50 years of age, premenopausal women should not be made on the basis of densitometric criteria alone. Bone biomarkers are a useful tool in detecting osteoporotic. A two-step dual-label time-resolved fluorescence immunoassay (TRFIA) was developed for the simultaneous detection of serum C-terminal telopeptide (β-CTX) and amino-terminal propeptide (P1NP) of Type I procollagen in a single run. The performance of this assay was first evaluated using clinical serum samples, and then compared with commercialized kits. The sensitivity of this assay for β-CTX was 1 ng/L (dynamic range, 0–1000 ng/L), and the sensitivity for P1NP detection was 1 μg/L (dynamic range, 1–1000 μg/L). High correlation coefficients (R) were obtained between the present dual-label TRFIA and commercially available kits (R = 0.99 for β-CTX and P1NP). The present dual-label TRFIA has high sensitivity, specificity and accuracy in clinical sample analysis. It is a good alternative to the single-label diagnostic methods.

Effect of a 6-week supervised detraining period on bone metabolism markers and their association with ergometrics and components of the hypothalamic-pituitary-gonadal (HPG) axis in professional male soccer players.

The aim of this study was to examine the effect of a supervised 6-week detraining period on bone metabolism markers, and their association with ergometrics, and components of the hypothalamic-pituitary-gonadal (HPG) axis in elite male professional soccer players. Sixty-seven soccer players (meanage ± SD 23.4 ± 5.2years) that were following a supervised training program participated in this study. Players were tested twice: immediately after the conclusion of the competition period, and following the detraining period, for the determination of bone-turnover rates, ergometrics, and components of the HPG-axis. The detraining period resulted in significant reduction in osteocalcin [OC] (p < 0.001), C-terminal propeptide of collagen type-I [CICP] (p = 0.002), and bone-alkaline-phosphatase [b-ALP] (p < 0.001) values, while C-terminal telopeptide [CTX] was increased (p < 0.001). No significant relationships were apparent between bone biomarkers and body weight, body-fat %, total testosterone, free testosterone, estradiol, follicle-stimulating hormone, and luteinizing hormone in both experimental sessions (p > 0.05). Similarly, despite the deterioration in ergometrics after detraining (all p < 0.001), no significant correlations were evident (p > 0.05) between bone biomarkers and maximal oxygen consumption, squat jump, countermovement jump, and 20m sprint performance, and also between % change of bone biomarkers and ergometrics, apart from a weak relationship (p = 0.041) between OC and VO2max of questionable value. Our results suggest that the 6-week soccer off-season detraining period in our study negatively affected bone physiology as reflected by the suppression of bone-formation rate and a parallel induction of bone resorption. The cause of this acute alteration of bone-turnover rates is not related to the examined components of the HPG-axis, although parallels is not associated with the changes in ergometrics.

Circular and Leaderless Bacteriocins: Biosynthesis, Mode of Action, Applications, and Prospects.

Bacteriocins are a huge family of ribosomally synthesized peptides known to exhibit a range of bioactivities, most predominantly antibacterial activities. Bacteriocins from lactic acid bacteria are of particular interest due to the latter’s association to food fermentation and the general notion of them to be safe. Among the family of bacteriocins, the groups known as circular bacteriocins and leaderless bacteriocins are gaining more attention due to their enormous potential for industrial application. Circular bacteriocins and leaderless bacteriocins, arguably the least understood groups of bacteriocins, possess distinctively peculiar characteristics in their structures and biosynthetic mechanisms. Circular bacteriocins have N-to-C- terminal covalent linkage forming a structurally distinct circular peptide backbone. The circular nature of their structures provides them superior stability against various stresses compared to most linear bacteriocins. The molecular mechanism of their biosynthesis, albeit has remained poorly understood, is believed to possesses huge application prospect as it can serve as scaffold in bioengineering other biologically important peptides. On the other hand, while most bacteriocins are synthesized as inactive precursor peptides, which possess an N-terminal leader peptide attached to a C-terminal propeptide, leaderless bacteriocins are atypical as they do not have an N-terminal leader peptide, hence the name. Leaderless bacteriocins are active right after translation as they do not undergo any post-translational processing common to other groups of bacteriocins. This “simplicity” in the biosynthesis of leaderless bacteriocins offers a huge commercial potential as scale-up production systems are considerably easier to assemble. In this review, we summarize the current studies of both circular and leaderless bacteriocins, highlighting the progress in understanding their biosynthesis, mode of action, application and their prospects.

Abstract P321: Substance P is Associated with Hypertension-induced Cardiac Fibrosis

Myocardial remodelling such as fibrosis is a major contributor to heart failure with preserved ejection fraction. We sought to determine the relationship between substance P (SP), a sensory neuropeptide, and this adverse remodelling. Using the angiotensin II mouse model of pressure overload we determined that Tac1 -/- mice that are genetically deficient in SP were protected from developing cardiac fibrosis (WT + Ang II = 1.452±0.1523% (n=9) vs Tac1 -/- + Ang II = 0.5678±0.078% (n=10), p&lt;0.0001). We then investigated the association between SP and fibrosis in hypertensive individuals. Plasma from consented individuals showed significantly higher levels of SP in the hypertensive group in comparison to the control group (control = 78.3 ±11.54 ng/mL (n=22), hypertensive = 127±17.5 ng/mL (n=43), p=0.023) (Figure). Interestingly, hypertensive males showed significantly higher levels of plasma SP than the male control group (control = 74.94±14.54 ng/mL (n=17), hypertensive = 143.2±23.96 ng/mL (n=29), p&lt;0.002), while no significant difference existed between these groups in females. Plasma levels of procollagen type 1 C-terminal pro-peptide (PICP), a marker of fibrosis, indicated that hypertensive individuals with SP levels greater than one standard deviation from the mean, had significantly higher levels of PICP (below = 5.539±0.688 ng/mL (n=38), above = 10.52±3.75 ng/mL (n=5), p=0.035). These findings indicate that high levels of plasma SP are associated with increased levels of a marker of fibrosis in hypertensive individuals. The human studies combined with the genetically modified mouse studies indicate an important role for SP in hypertension-induced cardiac fibrosis.