PINP Levels Research Articles

Collagen Remodeling Proteins, Inflammatory Biomarkers and FABP Regulation in Understanding the Pathogenesis of Atrial Fibrillation

IntroductionAtrial Fibrillation (AF) is the most common sustained form of cardiac arrythmia across the world with around 3 million active cases. Atrial fibrosis is the process by which collagen is deposited within the atria. Atrial fibrosis is correlated with AF. PINP and PICP, the two collagen remodeling proteins focused on in this study, are procollagen type I remodeling proteins and effective biomarkers of collagen deposition and bone formation. PINP exhibits diurnal variation with higher values occurring at night resulting in variance within the data set for PINP in AF patients. Long chain fatty acids (LCFAs), in excess, can lead to lipotoxicity which increases the risk of a potential arrythmia. Fatty Acid Binding Proteins (FABPs) bind to LCFAs to create a lower level of these fatty acid chains in the cytoplasm. Increased LCFAs has a direct correlation with increased FABPs which can ultimately increase the risk of arrythmia.PurposeThe purpose of this study was to analyze levels of collagen remodeling proteins, specifically PINP and PICP, and L‐FABP in an AF cohort to determine whether they can serve as viable biomarkers in the management and diagnosis of AF.HypothesisIt is expected that there will be an upregulation of collagen remodeling proteins, inflammatory biomarkers and FABP in AF patients compared to the NHP.Materials and MethodsThe study was conducted with a sample of 50 normal healthy human plasma and were tested for PINP, PICP, and FABP levels. These normal samples were purchased from George King Biomedical. The blood of the AF patients was collected following IRB protocol, centrifuged, and aliquoted at –80 degrees Celsius. AF plasma samples were analyzed using sandwich ELISA Kits. Results were statistically analyzed by using the IBM SPSS software and PRISM Graphpad.ResultsThe results were collected as mean ± SEM with a percent change of mean (%) to demonstrate upregulation. All three biomarkers PINP, PICP, and FABP demonstrated an upregulation, respectively, of (422.32 ± 43.78, 164.47%), (1.395902 ± 0.178727, 104.86%), and (13186.7517 ± 4256.96265, 157.75% with the outlier and 77.69% without outlier). All three biomarkers were statistically significant with p‐values of <0.0001, <0.01, and <0.0001 respectively for PINP, PICP, and FABP. There was a significant outlier in the FABP data at 295.778.86 pg/mL. This value created a skewness statistic of 7.502 which changed to 3.795 after the outlier was removed. There was a strong, positive correlation between the two collagen remodeling proteins, PICP and PINP, with an r‐value (correlation coefficient) value of 0.62.ConclusionThe results prove that increased structural remodeling, proven by higher levels of collagen remodeling proteins, can indicate AF. FABP had an evident upregulation in the AF patient, but the data was severely skewed right due to an outlier. Once the outlier was removed, the data still demonstrated an upregulation of 77.69%. Elevated levels of these biomarkers suggest that they can serve as surrogate endpoints in the management and diagnosis of AF.

Bone metabolism parameters and their relation to cytogenetics in multiple myeloma.

Our aim was to correlate serum levels of selected markers of bone metabolism and bone marrow microenvironment to cytogenetic changes in patients with multiple myeloma (MM). We assed cytogenetic changes in 308 patients and correlated them with the following levels of bone marrow metabolism: thymidine kinase (TK), β2-microglobulin (b-2-m), Dickkopf-1 protein (DKK-1), C-terminal telopeptide collagen-I (ICTP), N-terminal propeptide of type I procollagen (PINP), receptor for interleukin 6 (rIL-6), vascular cell adhesive molecule-1 (VCAM), soluble intercellular adhesion molecule-1, osteoprotegerin (OPG), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), syndecan-1 (SYN-1) and Fas antigen. Individuals with delRB1 had lower levels of OPG (M=7.39 vs. 5.46pmol/L, p=.025) and VEGF (M=304 vs. 196pg/ml; p=.036). t(14;16) was associated with higher β2m levels (M=7.59 vs. 4.13mg/L; p=.022) and lower DKK-1 levels (M=4465ng/L vs. 12,593). The presence of 1q21 gain was associated with higher levels of TK (M=100.0 vs. 11.0IU/L, p=.026) and lower levels of PINP (M=49.3 vs. 67.4mg/L, p=.030). Our analysis has shown, some cytogenetic changes, especially delRB1, t(14;16) and 1q21gain, which affect the components of the cytokine network in multiple myeloma.

Reduced Circulating Levels of miR-491-5p and miR-485-3p Are Associated with the Occurrence of Vertebral Fractures in Postmenopausal Women with Osteoporosis.

Objective Postmenopausal women experiences osteoporotic structural damage and bone fragility resulting from reduced bone formation and increased bone resorption. Osteoporosis frequently affects the vertebral column and causes compression fractures. This study aims to characterize roles of miRNAs in osteoporosis and subsequent incidence risk of vertebral fractures for postmenopausal women. Methods. Differentially expressed miRNAs between osteoporotic patients with vertebral fractures and osteoporotic patients without fracture were identified. This retrospective study included 78 osteoporotic patients with vertebral fractures and 82 osteoporotic patients without vertebral fractures. The plasma levels of bone metabolic markers, 25-hydroxyvitamin D (25-(OH)VitD), propeptide of type I procollagen (PINP), and β-Carboxyl terminal peptide (β-CTx), were detected using the patented electro-chemiluminescence (ECLIA) method. The expression levels of miR-491-5p and miR-485-3p were determined by qRT-PCR. Pearson correlation analysis was carried out to assess the relationship between miR-491-5p, miR-485-3p, and bone metabolic markers. Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were used to evaluate the performance of miR-491-5p and miR-485-3p in diagnosing the occurrence of vertebral fractures in osteoporotic patients.Results: The plasma levels of PINP and β-CTx were elevated but the plasma level of 25-(OH)VitD was declined in osteoporotic patients with vertebral fractures when comparable to those without (< 0.05). The plasma expression levels of miR-491-5p and miR-485-3p were declined osteoporotic patients with vertebral fractures when comparable to those without (< 0.001). Pearson correlation analysis revealed that the relative expression level of miR-491-5p was negatively correlated with the level of 25-(OH)VitD (r = -0.518, < 0.001) but positively correlated with the levels of PINP (r = 0.547, < 0.001) and β-CTx (r = 0.380, < 0.001). We also observed a negative correlation between the relative expression level of miR-485-3p and 25-(OH)VitD (r = -0.388, < 0.001), a positive correlation between miR-485-3p and PINP (r = 0.422,< 0.001). ROC curves for prediction of vertebral fracture following osteoporosis in postmenopausal women by miR-491-5p expression yielded 0.866 AUC and by miR-485-3p expression produced 0.848 AUC. Conclusion The data suggest that downregulated expressions of miR-491-5p and miR-485-3p may be involved in the occurrence of vertebral fractures in postmenopausal women with osteoporosis.

Fluctuations in Metabolites and Bone Markers Across the Menstrual Cycle in Eumenorrheic Women and Oral Contraceptive Users.

Little is known about changes in circulating metabolites during the menstrual cycle and how use of oral contraceptives (OCs) affects these changes. To study fluctuations in circulating metabolite and bone marker levels during the menstrual/pill cycle in eumenorrheic women and OC users. Plasma samples were collected from 28 eumenorrheic women and 10 OC users at 7 to 9 time points across a menstrual/pill cycle. Longitudinal and cross-sectional analyses were performed to examine the cycle- and OC-induced variations in the plasma metabolite and bone turnover marker levels. In eumenorrheic women, plasma levels of alanine, glutamine, threonine, and tyrosine varied significantly across the menstrual cycle, and all dropped to the lowest level around day 21 of the menstrual cycle. These amino acid concentrations were negatively correlated with fluctuations in progesterone and/or estrogen levels. A between-group analysis showed that plasma levels of alanine, glutamine, glycine, proline, and tyrosine were lower in OC users than in nonusers. Concomitantly, plasma C-terminal telopeptide of type I collagen (CTX) and N-terminal propeptide of type I procollagen (PINP) levels were lower in OC users. Intriguingly, when all data were pooled, variations in CTX and PINP levels were positively correlated with fluctuations in proline and glycine concentrations (r > 0.5 or 0.3 < r < 0.5, P < 0.05). The menstrual cycle and the use of OCs alter plasma levels of metabolites and bone turnover markers in young women. While the impact of these findings remains to be established, the lower glycine level among OC users and the accompanying lower CTX level supports that the use of OCs lowers collagen turnover in young women and may thereby have long-term implications for bone health among OC users.

Sheep bone collagen peptide ameliorates osteoporosis by regulating RANK/RANKL/OPG signal pathway

Sheep bone collagen peptide (SBCP) has attracted attention due to its potential effects on bone health. This study aims to explore the bone protective effect of SBCP in the presence of estrogen deficiency. Ovariectomized (OVX) female rats were given different dose rates (0, 0.68, 2.05, 3.40 g/kg BW) of SBCP for 8 consecutive weeks. At the end of the treatment, the serological indexes and tibial mineral content were measured. The microstructure and morphological changes of femur bones were observed by scanning electron microscopy (SEM) and hematoxylin and eosin (H & E) staining. Femur bones were harvested for determination of expression level of RANK, RANKL, OPG by molecular biological techniques. 3.40 g/kg BW SBCP treatment decreased the PINP and β-CTx levels but increased the tibial calcium and phosphorus contents significantly in estrogen deficient rats. Expression of RANK and RANKL decreased however expression of OPG increased in the bone of estrogen deficient rats which received 3.40 g/kg BW SBCP with greater effects than SBCP-M and SBCP-L treatments. SBCP helps to overcome the adverse effect of estrogen deficiency the bone and thus this nutriment could potentially be used for the treatment and prevention of osteoporosis in postmenopausal women.

Discontinuation of PTH therapy amplifies bone loss by increasing oxidative stress: An event ameliorated by sequential IL-17 neutralizing antibody therapy.

Osteoporosis leads to excessive bone resorption which is not accompanied by equal amount of bone formation. PTH (1-34) forms the mainstay of bone anabolic therapy. Intermittent PTH (iPTH) has the ability to reconstruct skeleton, a property not shared by other anti-resorptives. In initial phases of PTH treatment, bone formation exceeds bone resorption. However, gradually this phase is replaced by increased bone resorption. Thus, a replacement post PTH discontinuation is much needed. Studies with bisphosphonates and Denosumab post PTH withdrawal have yielded promising but variable results. Thus, there is scope for trying new combinations. Our previous studies have shown the superior skeletal effects of neutralizing IL17 antibody (NIL17) over anti-RANKL antibody. Thus, here we investigated if sequential treatment of NIL17 after PTH withdrawal (SHIFT) could serve as a promising therapeutic approach for osteoporosis treatment. Our results show that PTH withdrawal (PTH-W) led to mitigation of its anabolic effects as evidenced by reduced BMD, bone trabecular and cortical microarchitectural parameters. In the continuous PTH (PTH-C) and the Shift group, all these parameters were preserved as par with the sham group. Shift therapy also significantly increased PINP levels. Most importantly, serum CTX-I levels and osteoclast numbers, which were elevated in PTH groups were significantly suppressed in NIL17 monotherapy and shift group. Also, expression of FOXO1 and ATF-4, the main regulators of redox balance and function in osteoblasts, were found to be enhanced maximally in the sequential therapy group. Our study thus advocates use of NIL17 as a replacement therapeutic option post PTH discontinuation.

Application of bone metabolic parameters in the diagnosis of growing pains.

ObjectiveThe present study aimed to assess the diagnostic significance of serum bone metabolic parameters in children with growing pains (GPs).MethodsAll patients diagnosed with GP and healthy controls matched with age and gender were recruited at the outpatient clinic of Children's Hospital at Zhejiang University School of Medicine from August 2016 to August 2021. In all subjects, serum levels of calcium (Ca), phosphorus (P), procollagen type‐I N‐terminal (PINP), parathormone (PTH), 25‐hydroxyvitamin D (25‐(OH)D), osteocalcin (OC), N‐terminal cross‐linked telopeptides of type‐I collagen (CTX), and tartrate‐resistant acid phosphatase type 5b (TRACP5b) were investigated. The univariate analysis, multivariate logistic regression analysis, and receiver operating characteristic (ROC) curve were used to identify the bone metabolic parameters factors for diagnosing GP.ResultsWe enrolled 386 children with GP and 399 healthy controls in present study. The mean age of GP group was 5.319 years, and, primarily, the subjects were preschool‐age children. The gender ratio (male‐to‐female) was 1.27 in GP group. After adjusting for age and gender, we identified that the serum levels of Ca (p < 0.001, OR: 25.039), P (p = 0.018, OR: 2.681), PINP (p < 0.001, OR: 1.002), and PTH (p = 0.036, OR: 0.988) were independent diagnostic factors associated with GP. Area under curve (AUC) of the ROC curves was in the order: PINP (0.612) > Ca (0.599) > P (0.583) > PTH (0.541). A combination of independent diagnostic factors and multivariable logistic regression analysis provided a refined logistic regression model to improve the diagnostic potential, of which the AUC had reached 0.655.ConclusionsSerum levels of Ca, P, PINP, and PTH could be independent diagnostic factors associated with GP. The logistic model was significantly superior to bone metabolic parameters for diagnosing GP.

Ovariectomy-Induced Dysbiosis May Have a Minor Effect on Bone in Mice.

We determined the bone mineral density (BMD) and the expression of serum bone formation marker (procollagen type I N-terminal propeptide: PINP) and bone resorption marker (C-terminal telopeptide of collagen: CTX) by ELISA to evaluate ovariectomy-induced osteoporosis in ovariectomized (OVX) mice. The intestinal microbiota of the mice was assessed using 16S rRNA gene sequencing. OVX mice exhibited a lower BMD of 87% with higher serum levels of CTX and PINP compared to sham-operated (sham) mice. The cecum microbiome of OVX mice showed lower bacterial diversity than that of sham mice. TNFα mRNA levels in the colon were 1.6 times higher, and zonula occludens-1 mRNA and protein expression were lower in OVX mice than in sham mice, suggesting that ovariectomy induced inflammation and increased intestinal permeability. Next, we used antibiotic treatment followed by fecal microbiota transplantation (FMT) to remodel the gut microbiota in the OVX mice. A decrease in PINP was observed in antibiotic-treated mice, while there was no change in BMD or CTX between mice with and without antibiotic treatment. Oral transplantation of the luminal cecal content of OVX or sham mice to antibiotic-treated mice did not affect the BMD or PINP and CTX expression. Additionally, transplantation of the luminal contents of OVX or sham mice to antibiotic-treated OVX mice had similar effects on BMD, PINP, and CTX. In conclusion, although ovariectomy induces dysbiosis in the colon, the changes in the gut microbiota may only have a minor role in ovariectomy-induced osteoporosis.

Bone turnover markers in gingival crevicular fluid and blood serum of patients with fixed orthodontic appliances.

Bone remodelling can be followed through the bone turnover markers (BTMs). Aim of the present study was to record the fluctuation of an osteoclastic and an osteoblastic BTM [C-terminal telopeptide of type I collagen (CTX) and N-terminal pro-peptide of type I pro-collagen (PINP), respectively] in both the gingival crevicular fluid (GCF) and the serum of orthodontic patients before and after the initial application of orthodontic forces. Twenty-one Caucasian patients were prospectively evaluated. GCF and blood samples were collected in order to measure the selected biomarkers by ELISA at three time-points: exactly before, 5 days, and 14 days after bonding of the appliances. Standardized sample handling and patient preparation procedures were adopted in order to reduce pre-analytical variability. GCF and serum CTX levels were found to be independent of age, although higher in the serum of female subjects. PINP levels were found higher in the serum of patients ≥25 years old, as well as in the GCF of males. A positive correlation between serum and GCF baseline PINP levels was observed. The effect of orthodontic treatment on bone remodelling might not be absolutely representative of the local bone microenvironment as the levels of the specific BTMs where measured within the GCF of the lower front teeth. This is the first time PINP and CTX have been evaluated in the GCF and serum of orthodontic patients with fixed appliances. No statistically significant alterations of CTX and PINP levels in the GCF and the serum of patients were recorded over time during the initial stages of orthodontic treatment.

Impact of Daratumumab Monotherapy on Bone Metabolism Parameters in Patients with Relapsed and/or Refractory Multiple Myeloma Who Have Received at Least Two Prior Lines of Therapy Including Lenalidomide and a Proteasome Inhibitor: Outcomes of the Phase 2 Rebuild Study

Impact of Daratumumab Monotherapy on Bone Metabolism Parameters in Patients with Relapsed and/or Refractory Multiple Myeloma Who Have Received at Least Two Prior Lines of Therapy Including Lenalidomide and a Proteasome Inhibitor: Outcomes of the Phase 2 Rebuild Study

Evaluation of bone metabolism-associated biomarkers in Tibet, China.

AimTo measure and evaluate the distribution and possible contributing factors of seven bone metabolism‐associated biomarkers in Tibet, a plateau province of China.MethodsA total of 1615 individuals were recruited from Tibet at three different altitudes. The levels and possible contributing factors of serum calcium, serum phosphorus, ALP, 25OHD, PINP, CTX, and PTH were evaluated.ResultsIn total, 1246 Tibetan adults (males: n = 543) were eventually enrolled in this study. Multiple linear regression recognized age, sex, altitude, and BMI as the major effect factors. The levels of ALP, PINP, and CTX in males continuously decreased with age; however, those in females increased after approximately 39 years of age. Males had higher 25OHD levels (23.9 vs. 15.4 ng/ml) but lower levels of serum phosphorus (1.12 vs. 1.19 mmol/L) and PTH (41.3 vs. 47.4 pg/ml) than females. Before the age of 50, males had higher levels of calcium, ALP, PINP, and CTX than females, and the opposite trend was observed after the age of 50. The highest levels of serum calcium and phosphorus and the lowest levels of PINP and CTX were found in the Shigatse/Lhasa region, suggesting a better bone metabolism status. Compared with reports from plain areas of China, significantly higher levels of PINP (65.3 vs. 49.36 ng/ml) and CTX (0.46 vs. 0.37 ng/ml) were recorded in Tibetan adults.ConclusionA more active bone turnover status was found in Tibetan adults than in individuals from the plain areas of China.

Age-related changes and reference intervals of RANKL, OPG, and bone turnover markers in Indian women.

The aim of the study was to establish reference interval for RANKL, OPG, RANKL/OPG, and bone turnover markers CTX and PINP in healthy Indian women. This was a cross-sectional study on 374 healthy Indian women in the age group of 20-65years. Serum levels of total RANKL, OPG, CTX, PINP, and estradiol were determined by commercial ELISA kits. The reference intervals for these cytokines and bone turnover markers were based on the 95% centrally distributed data. Median RANKL (245.6pmol/L vs. 149pmol/L) and RANKL/OPG (38.7 vs. 20.4) were higher, while sCTX (380ng/L vs. 551ng/L) and OPG levels (6.1pmol/L vs. 7.4pmol/L) were lower in premenopausal women than those in postmenopausal women. PINP levels were comparable in both groups. Women were classified into 5 groups according to decades of age and the reference intervals for RANKL, OPG, RANKL/OPG ratio, and CTX and PINP in each group were reported. We reported menopausal status-based and age-related reference intervals for serum RANKL, OPG, RANKL/OPG ratio, and CTX and PINP in healthy Indian women.

Уровень N-терминального пропептида проколлагена І типа в сыворотке крови у людей разного возраста и пола

Целью исследования является определение уровня N-терминального пропептида проколлагена І типа (PINP) в сыворотке крови у здоровых мужчин и женщин всех возрастов. Материалы и методы. В исследование были включены 1568 человек (1422 лица женского и 146 — мужского пола) в возрасте 20–89 лет (средний возраст — 60,36 ± 13,68 года). Всех пациентов разделили на 7 групп, в соответствии с десятилетиями и геронтологической классификацией возраста: молодой возраст — 20–44 года, средний — 45–59 лет, пожилой — 60–74 года и старческий возраст — 75–89 лет. Во время исследования изучали влияние демографических характеристик (возраста и пола) на уровень PINP в сыворотке крови методом электрохемилюминесцентного иммуноанализа ECLIA на анализаторе cobas e 411. Результаты. В результате исследования у женщин не выявлено достоверного влияния возраста на вариабельность PINP в сыворотке крови (F = 1,453, р = 0,19). Выявлено достоверное снижение уровня PINP в возрастных группах: 40–49 лет (47,74 ± 21,31, р = 0,02), 60–69 лет (49,76 ± 25,75, р = 0,03), 70–79 лет (50,49 ± 26,71, р = 0,04), по сравнению с возрастной группой 20–29 лет (58,67 ± 27,46). По результатам регрессионного анализа выявлено достоверное снижение уровня PINP с возрастом у молодых женщин и мужчин (20–44 лет). При сравнении уровня PINP в сыворотке крови у представителей старшей возрастной группы (80–89 лет) обнаружено его повышение у женщин (55,20 ± 28,38 нг/мл) по сравнению с группой 70–79 лет (50,49 ± 26,71 нг/мл) и снижение у мужчин (54,87 ± 28,24 нг/мл и 39,16 ± 12,46 нг/мл соответственно). У мужчин обнаружено вероятное влияние возраста на вариабельность PINP в сыворотке крови (F = 3,08, р = 0,007). Выводы. По результатам регрессионного анализа установлено достоверное снижение уровня PINP с возрастом у мужчин и женщин 20–44 лет. Доказано вероятное влияние возраста на вариабельность PINP в сыворотке крови у мужчин. При сравнении уровня PINP в сыворотке крови у представителей старшей возрастной группы (80–89 лет) выявлено его повышение у женщин по сравнению с группой 70–79 лет и снижение у мужчин. Полученные нами результаты могут быть использованы как референтные данные уровня PINP в сыворотке крови у представителей украинской популяции разного возраста и пола.

Low serum osteocalcin levels are associated with diabetes mellitus in glucocorticoid treated patients.

Osteocalcin (OC) is involved in the regulation of glucose homeostasis. Glucocorticoid (GC) treatment is associated with impaired osteoblast function, decreased OC levels, and the development and/or worsening of pre-existing diabetes mellitus (DM). Whether decreased OC levels in GC-treated subjects contribute to DM is not well known. The aim of this study was to analyse whether OC levels in GC-treated patients are associated with the presence of DM. One hundred twenty-seven patients (aged 61.5 ± 17.9years) on GC treatment were included. GC dose, treatment duration, presence of DM and bone formation (OC, bone ALP, PINP) and resorption markers (urinary NTX, serum CTX) were analysed. The cut-offs of each bone turnover marker (BTM) for the presence of DM were evaluated and optimised with the Youden index and included in the logistic regression analysis. Among the patients, 17.3% presented DM. No differences were observed in GC dose or duration or the presence of fractures. Diabetics showed lower levels of OC (7.57 ± 1.01 vs. 11.56 ± 1; p < 0.001), PINP (21.48 ± 1.01 vs. 28.39 ± 1; p = 0.0048), NTX (24.91 ± 1.01 vs. 31.7 ± 1; p = 0.036) and CTX (0.2 ± 1.01 vs. 0.3 ± 1; p = 0.0016). The discriminating BTM cut-offs for DM presence were < 9.25ng/mL for OC, < 24ng/mL for PINP, < 27.5nMol/mM for NTX and < 0.25ng/mL for CTX. In a multivariate logistic regression model adjusted for GC dose, BMI, age and the above four BTMs, only OC remained independently associated with DM presence. Thus, in a model adjusted for GC dose, BMI and age, OC was significantly associated with DM (OR: 6.1; 95%CI 1.87-19.89; p = 0.001). Decreased OC levels in GC-treated patients are associated with increased odds of DM, and only OC was independently associated with DM in a model including four BTMs.

Effects of palliative radiotherapy and bisphosphonate usage on bone turnover marker levels in cancer patients with osteolytic bone metastases.

Objectives In this study, we aimed to investigate the bone turnover marker levels according to bisphosphonate usage and radiotherapy (RT) in cancer patients with metastases in osteolytic pattern.Patients and methods A total of 52 patients (13 males, 39 females; median age: 52 years; range, 37 to 78 years) treated with RT for osteolytic bone metastases between April 2005 and April 2006 were retrospectively analyzed. Bone-specific alkaline phosphatase (BAP), amino-terminal cross-linked telopeptide of type I collagen (NTX-I), amino-terminal propeptide of type I procollagen (PINP), osteocalcin (OC), deoxypyridinoline (DPD), pyridinoline (PYD), alkaline phosphatase (ALP), creatinine, calcium (Ca), phosphate (P), magnesium (Mg), and 24-h urine Ca levels were measured in blood and urine before the initiation of RT, six weeks and six months after RT.Results A decrease in BAP, PINP, and creatinine levels was observed after RT (Week 6 p=0.006, Month 6 p=0.008). Sixteen patients who already used bisphosphonate before RT were excluded from statistical calculation. The remaining 36 patients who were treated with bisphosphonate after the first blood test were evaluated separately. In this group of patients, BAP, PINP, NTX, creatinine, and Ca levels significantly increased at six weeks after RT. The PINP and creatinine values significantly decreased at six months after RT. The variation between two different RT arms was assessed with repeated measures variance analysis. There was a statistically significant difference for NTX, OC, and creatinine levels between the first and second measurements.Conclusion Radiotherapy is an effective method in the treatment of osteolytic bone metastases. Bone turnover markers can provide an objective evaluation on RT response and parallel to imaging modalities criteria for evaluation. Bisphosphonates may alter the levels of these indicators. However, in this study, there were no statistically significant differences between the levels of markers for two different RT schedules.

Molecular mechanisms of left atrial fibrosis development in patients with atrial fibrillation and metabolic syndrome: what biomarkers should be used in clinical practice?

Aim. To determine the blood concentration of fibrosis biomarkers in patients with atrial fibrillation (AF) in combination with metabolic syndrome (MS) and to analyze the relationship with myocardial fibrosis.Material and methods. This cross-sectional case-control study included 547 patients aged 35 to 65 years: experimental group — patients with MS (n=373), of which 202 patients had AF; comparison group — AF patients without MS (n=110); healthy subjects without cardiovascular diseases and metabolic disorders (n=64). Patients with AF and MS who underwent electroanatomic mapping before pulmonary vein isolation (n=79) were assessed for left atrial (LA) fibrosis severity.Results. It was found that the blood concentration of circulating profibrogenic biomarkers in patients with AF and MS is higher than in patients with AF without MS: aldosterone (135,1 (80,7-224,1) and 90,1 (68,3-120,3) pg/ml, p&lt;0,0001), galectin-3 (10,6 (4,8-15,4) and 5,8 (4,8-8,3) pg/ml, p=0,0001), GDF15 (938,3 (678,3-1352,1) and 671,0 (515,7-879,5) pg/ml, p=0,001), TGF-beta-1 (4421,1 (2513,5-7634,5) and 2630,5 (2020,7-3785,4) pg/ml, p=0,001), CTGF (167,8 (78,9-194,3) and 124,3 (74,4-181,9) pg/ml, p&lt;0,0001), PIIINP (88,5 (58,6120,4) and 58,9 (40,7-86,1) ng/ml, p&lt;0,0001), PINP (3421,4 (1808,1-4321,7) and 2996,1 (2283,8-3894,3) pg/ml, p&lt;0,0001). Patients with paroxysmal AF have higher concentrations of TGF-beta1, CTGF and PINP than patients with persistent and permanent AF. In patients with persistent AF and MS, the concentrations of galectin-3, aldosterone, and PIIINP were higher than in patients with paroxysmal AF, while in patients with permanent AF, they were significantly lower. The plasma concentration of galectin-3 positively correlated with levels of PINP (p=0,465, p&lt;0,0001), PIIINP (p=0,409, p&lt;0,0001), GDF-15 (p=0,369, p&lt;O,O001), CTGF (p=0,405, p&lt;0,0001). According to multivariate regression, of all studied biomarkers, GDF-15 had a greater effect on PIIINP concentration (в=0,234, p=0,038), and galectin-3 — on PINP (в=0,248, p&lt;0,021). Positive correlations of the severity of left atrial fibrosis with the concentration of galectin-3 (p=0,563, p&lt;0,0001), PINP (p=0,620, p&lt;0,0001), TGF-beta-1 (p=0,390, p&lt;0,0001) and CTGF (p=0,551, p&lt;0,0001). According to linear multivariate regression, the most significant effect on LA fibrosis severity among the studied biomarkers is exerted by galectin-3 (в=0,432, p&lt;0,0001), PINP (в=0,343, p=0,001) and PIIINP (в=0,286, p=0,008).Conclusion. An increase in the blood concentration of profibrogenic biomarkers galectin-3, TGF-beta-1, CTGF, PIIINP, and PINP is associated with an increase in LA fibrosis severity and probably has a pathogenetic role in increasing the AF risk in patients with MS.

Antiepileptic Stiripentol May Influence Bones.

Bone structure abnormalities are increasingly observed in patients chronically treated with antiepileptic drugs (AEDs). The majority of the available data concern older conventional AEDs, while the amount of information regarding newer AEDs, including stiripentol, is limited. The aim of the study was to assess the effect of stiripentol on bones. For 24 weeks, male Wistar rats, received 0.9% sodium chloride (control group) or stiripentol (200 mg/kg/day) (STP group). In the 16th week of the study, we detected lower serum PINP levels in the STP group compared to the control group. In the 24th week, a statistically significant lower 1,25-dihydroxyvitamin D3 level, higher inorganic phosphate level and higher neutrophil gelatinase-associated lipocalin (NGAL) levels in serum were found in the STP group compared to the control. Micro X-ray computed tomography of the tibias demonstrated lower bone volume fraction, lower trabecular thickness, higher trabecular pattern factor and a higher structure model index in the stiripentol group. Considering the results of this experiment on rats which suggests that long-term administration of stiripentol may impair the cancellous bone microarchitecture, further prospective human studies seem to be justified. However, monitoring plasma vitamin D, calcium, inorganic phosphate and kidney function in patients on long-term stiripentol therapy may be suggested.

Abstract 1392: Synergistic antitumor efficacy of radium-223 in combination with enzalutamide in the intratibial LNCaP prostate cancer xenograft model

Abstract Radium-223 dichloride (Ra-223) is a targeted alpha therapy that binds to newly formed bone matrix in bone metastases and induces DNA double-strand breaks in cancer cells, osteoblasts and osteoclasts. It is used for treating men with castration-resistant prostate cancer (CRPC) and bone metastases. Enzalutamide is a second-generation androgen receptor inhibitor also used for treating the same patient population, and the combination of Ra-223 and enzalutamide is currently being investigated in clinical trials. We evaluated the antitumor efficacy of Ra-223 and enzalutamide in the LNCaP intratibial model mimicking prostate cancer metastasized to bone. LNCaP prostate cancer cells were inoculated into the right tibia of male NOD.scid mice. The mice were randomized (n=9/group) based on serum PSA and treated with vehicle, Ra-223 (330 kBq/kg, i.v., Q4W x 2), enzalutamide (30 mg/kg, p.o., QD) or with a combination treatment of Ra-223 and enzalutamide, for 28 days. Serum PSA levels were analyzed at the end of the study and compared to the pre-treatment levels. Serum bone formation and resorption biomarkers, PINP and CTX, respectively, were measured during the study. Tumor-induced abnormal bone area, Ra-223 uptake and bone formation were determined by X-ray, gamma counter and histomorphometry, respectively. The healthy tibiae were evaluated by microCT. Combination treatment showed synergistic antitumor efficacy as observed by lower PSA levels when compared to the vehicle, Ra-223 or enzalutamide monotherapies (p=0.04, p=0.008 and p=0.002, respectively). A statistical interaction between Ra-223 and enzalutamide treatments was found (p=0.003), confirming the synergistic effect. In combination treatment, the serum PSA change relative to pre-treatment levels was 18% of the vehicle. Accordingly, a decreasing trend (p=0.08) in tumor-induced abnormal bone changes was associated with the combination treatment in the tumor-bearing tibiae (46% of the vehicle), whereas no changes in total bone structure were observed in the healthy tibiae. The serum levels of PINP and CTX were lowest in mice treated with the combination treatment. Compared to Ra-223 monotherapy, concurrent administration of enzalutamide with Ra-223 did not affect either Ra-223 uptake or bone formation rate in tumor-bearing or healthy tibiae, respectively. Compared to Ra-223 and enzalutamide monotherapies, the combination treatment demonstrated synergistic antitumor efficacy by decreasing PSA levels in the LNCaP intratibial model. Despite of prominent effects on tumor growth, the combination treatment was not observed to compromise bone health in the healthy tibiae. In conclusion, these preclinical results support the ongoing phase 3 trials PEACE III (NCT02194842) &amp; ESCALATE (NCT04237584) of this combination. Citation Format: Mari I. Suominen, Matias Knuuttila, Jukka Vääräniemi, Birgitta Sjöholm, Esa Alhoniemi, Dominik Mumberg, Sanna-Maria Käkönen, Arne Scholz. Synergistic antitumor efficacy of radium-223 in combination with enzalutamide in the intratibial LNCaP prostate cancer xenograft model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1392.

Bone Metabolism and RANKL/OPG Ratio in Rheumatoid Arthritis Women Treated with TNF-α Inhibitors.

The aim of this study was to evaluate the effect of anti-tumor necrosis factor α (anti-TNF-α) therapy in combination with methotrexate on bone remodeling and osteoclastogenesis in female patients with RA. Serum levels of bone turnover markers (i.e., C- and N-terminal propeptides of type I procollagen (PICP and PINP), C- and N-terminal cross-linking telopeptides of type I collagen (CTX-I and NTX-I), and soluble receptor activator of nuclear factor κB ligand (sRANKL) and osteoprotegerin (OPG)) were determined by immunoassay at baseline and 15 months after initiation of treatment. Bone mineral density was measured by dual-energy x-ray absorptiometry. We found a significant decrease in serum PINP levels, a biomarker of bone formation, and higher levels of CTX-I and sRANKL indicative of increased bone resorption in RA patients prior to TNFαI treatment compared to the controls. Anti-TNF-α therapy was effective in improving bone metabolism in RA patients as reflected in a decrease in CTX-I (at least partially due to the RANKL/OPG reduction) and a concomitant increase in PINP levels. The bone metabolism changes were independent of the type of TNFαI used. PINP and CTX-I were found to be useful markers of bone metabolism, which may prove the effectiveness of TNF-α therapy earlier than the bone density assessment.

Fructus Ligustri Lucidi aqueous extract promotes calcium balance and short-chain fatty acids production in ovariectomized rats

Ethnopharmacological relevanceFructus Ligustri Lucidi (FLL) is an edible herb with anti-osteoporotic activity, yet whether and how the aqueous extract of this herb affect calcium metabolism in preservation of bone quality remain unclear. Aim of the studyTo investigate the effects of FLL aqueous extract on calcium balance and short-chain fatty acids (SCFAs) production in ovariectomized (OVX) rats. Materials and methodsOVX rats were daily and orally administrated with FLL aqueous extract (3.5 g/kg) for 14 weeks. The levels of N-terminal propeptide of type I collagen (PINP) and C-terminal telopeptide of type I collagen (CTx-I) in rat serum were evaluated by ELISA assays. The concentration of calcium in serum, urine, and feces were determined by biochemical assays. Bone quality was determined by Micro-CT, a three-point bending assay, and Fourier Transform Infrared (FTIR) Spectrometry. The expressions of Calbindin D28K and Calcium-sensing receptor (CaSR) in kidney as well as the Vitamin D receptor (VDR), the transient receptor potential vanilloid receptor 6 (TRPV6), Calbindin D9k in the duodenum were measured by immunohistochemistry, western blotting, or real-time PCR. The short-chain fatty acids (SCFAs) levels in the feces of the cecum were tested by gas chromatograghy. ResultsThe administration of FLL to OVX rats resulted in a significant improvement in bone mineral density and biomechanical strength as well as in maintaining bone microstructures and material quality. Meanwhile, the decreased levels of PINP and increased levels of CTx-I in OVX rats were restored by FLL treatment. Additionally, FLL treatment increased calcium absorption, upregulated VDR, TRPV6, Calbindin D9k expressions in the duodenum, Calbindin D28K in kidney, and down-regulated CaSR expression in the kidney, as well as enhanced SCFAs levels in the feces of OVX rats. ConclusionsFLL aqueous extract may preserve bone quality through regulation of the calcium balance and intestinal SCFAs production in OVX rats. This offers translational value of FLL into osteoporosis clinical trial.