Novel osteogenic peptide from bovine bone collagen hydrolysate: Targeted screening, molecular mechanism, and stability analysis.

This study aimed to screen for a novel osteogenic peptide based on the calcium-sensing receptor (CaSR) and explore its molecular mechanism and gastrointestinal stability. In this study, a novel osteogenic peptide (Phe-Ser-Gly-Leu, FSGL) derived from bovine bone collagen hydrolysate was successfully screened by molecular docking and synthesised by solid phase peptide synthesis for further analysis. Cell experiments showed that FSGL significantly enhanced the osteogenic activity of MC3T3-E1 cells by acting on CaSR, including proliferation (152.53%), differentiation, and mineralization. Molecular docking and molecular dynamics further demonstrated that FSGL was a potential allosteric activator of CaSR, that turned on the activation switch of CaSR by closing the Venus flytrap (VFT) domain and driving the two protein chains in the VFT domain to easily form dimers. In addition, 96.03% of the novel osteogenic peptide FSGL was stable during gastrointestinal digestion. Therefore, FSGL showed substantial potential for enhancing the osteogenic activity of osteoblasts. This study provided new insights for the application of CaSR in the targeted screening of osteogenic peptides to improve bone health.

Phosphorylation modification of bovine bone collagen peptide enhanced its effect on mineralization of MC3T3-E1 cells via improving calcium-binding capacity.

This study aimed to investigate the effect of phosphorylation modification of collagen peptide on its calcium-binding capacity and pro-mineralization activity. In this study, collagen peptide (Leu-Thr-Phe, LTF) and phosphorylated LTF (P-LTF) were synthesized and further chelated with calcium ions. The results showed that phosphorylation of LTF significantly enhanced its calcium-binding capacity. Spectra analysis revealed that the calcium-binding sites of P-LTF were mainly carbonyl, carboxyl, and phosphate groups. Molecular docking further demonstrated that the phosphate group introduced by phosphorylation enhanced the calcium-binding capacity of LTF by ionic bonds and coordination bonds. The stability analysis results suggested that intestinal fluid could repair the peptide-calcium complex destroyed by gastric fluid. The cell experiment displayed that P-LTF-Ca significantly improved the mineralization activity of MC3T3-E1 cells, and the order of effective influence was P-LTF-Ca > LTF-Ca > P-LTF > LTF. This study provided the theoretical basis for the potential application of phosphorylation modification in improving bone health.

Novel Calcium-Binding Peptide from Bovine Bone Collagen Hydrolysates and Its Potential Pro-Osteogenic Activity via Calcium-Sensing Receptor (CaSR).

SCOPE: This paper aims to explore the osteogenic activity and potential mechanism of the peptide-calcium chelate, and provides a theoretical basis for peptide-calcium chelates as functional foods to prevent or improve osteoporosis. METHODS AND RESULTS: In this research, a novel peptide (Phe-Gly-Leu, FGL) with a high calcium-binding capacity is screened from bovine bone collagen hydrolysates (CPs), calcium binding sites of which mainly included carbonyl, amino and carboxyl groups. The FGL-Ca significantly enhances the osteogenic activity of MC3T3-E1 cells (survival rate, differentiation, and mineralization). The results of calcium fluorescence labeling and molecular docking show that FGL-Ca may activate calcium-sensing receptor (CaSR), leading to an increase in intracellular calcium concentration, then enhancing osteogenic activity of MC3T3-E1 cells. Further research found that FGL-Ca significantly promotes the mRNA and protein expression levels of CaSR, transforming growth factor ß (TGF-ß1), TGF-ß-type II receptor (TßRII), Smad2, Smad3, osteocalcin (OCN), alkaline phosphatase (ALP), osteoprotegrin (OPG), and collagen type I (COLI). Subsequently, in the signal pathway intervention experiment, the expression levels of genes and proteins related to the TGF-ß1/Smad2/3 signaling pathway that are promoted by FGL-Ca are found to decrease. CONCLUSIONS: These results suggest that FGL-Ca may activate CaSR, increase intracellular calcium concentration, and activate TGF-ß1/Smad2/3 signaling pathway, which may be one of the potential mechanisms for enhancing osteogenic activity.

Individual Trajectories of Health Status During the First Year of Discharge From Hospitalization for Heart Failure and Their Associations With Death in the Following Years.

Background Improving health status is one of the major goals in the management of heart failure (HF). However, little is known about the long-term individual trajectories of health status in patients with acute HF after discharge. Methods and Results We enrolled 2328 patients hospitalized for HF from 51 hospitals prospectively and measured their health status via the Kansas City Cardiomyopathy Questionnaire-12 at admission and 1, 6, and 12 months after discharge, respectively. The median age of the patients included was 66 years, and 63.3% were men. Six patterns of Kansas City Cardiomyopathy Questionnaire-12 trajectories were identified by a latent class trajectory model: persistently good (34.0%), rapidly improving (35.5%), slowly improving (10.4%), moderately regressing (7.4%), severely regressing (7.5%), and persistently poor (5.3%). Advanced age, decompensated chronic HF, HF with mildly reduced ejection fraction, HF with preserved ejection fraction, depression symptoms, cognitive impairment, and each additional HF rehospitalization within 1 year of discharge were associated with unfavorable health status (moderately regressing, severely regressing, and persistently poor) (P<0.05). Compared with the pattern of persistently good, slowly improving (hazard ratio [HR], 1.50 [95% CI, 1.06-2.12]), moderately regressing (HR, 1.92 [1.43-2.58]), severely regressing (HR, 2.26 [1.54-3.31]), and persistently poor (HR, 2.34 [1.55-3.53]) were associated with increased risks of all-cause death. Conclusions One-fifth of 1-year survivors after hospitalization for HF experienced unfavorable health status trajectories and had a substantially increased risk of death during the following years. Our findings help inform the understanding of disease progression from a patient perception perspective and its relationship with long-term survival. Registration URL: https://www.clinicaltrials.gov; unique identifier: NCT02878811.

Impact of Ultrasonication on the Self-Assembly Behavior and Gel Properties of Bovine Bone Collagen I.

This study deliberated the effect of ultrasonic treatment on collagen self-assembly behavior and collagen fibril gel properties. Bovine bone collagen I which had undergone ultrasonic treatment with different power (0-400 W) and duration (0-60 min) was analyzed. SDS-PAGE and spectroscopic analysis revealed that ultrasonic treatment decreased collagen molecular order degree and the number of hydrogen bonds, stretching collagen telopeptide regions while maintaining the integrity of the collagen triple-helical structure. Ultrasonic treatment (p ≤ 200 W, t ≤ 15 min) dispersed the collagen aggregates more evenly, and accelerated collagen self-assembly rate with a decreased but more homogeneous fibril diameter (82.78 ± 16.47-115.52 ± 19.51 nm) and D-periodicity lengths (62.1 ± 2.9-66.5 ± 1.8 nm) than that of the untreated collagen (119.15 ± 27.89 nm; 66.5 ± 1.8 nm). Meanwhile, ultrasonic treatment (p ≤ 200 W, t ≤ 15 min) decreased the viscoelasticity index and gel strength, enhancing thermal stability and promoting specific surface area and porosity of collagen fibril gels than that of the untreated collagen fibril gel. These results testified that collagen self-assembly behavior and collagen fibril gel properties can be regulated by ultrasonic treatment through multi-hierarchical structural alteration. This study provided a new approach for controlling in vitro collagen fibrillogenesis process so as to manufacture novel desirable collagen-based biomaterials with propitious performances for further valorization.

A novel calcium-binding peptide from bovine bone collagen hydrolysate and chelation mechanism and calcium absorption activity of peptide-calcium chelate.

A novel calcium-binding peptide from bovine bone collagen hydrolysate was screened based on a new target-the calcium-sensing receptor (CaSR), and its chelation mechanism and calcium absorption activity were investigated. Glu-Tyr-Gly exhibited superior binding affinities to CaSR because of its interaction with the active sites of the CaSR Venus Flytrap (VFT) domain. Glu-Tyr-Gly-Ca may exist in five potential chelation modes and its potential chelation mechanism was that calcium ions were located in the center and surrounded by ionic bonds (carboxyl group) and coordination bonds (carbonyl, amino, and carboxyl group). Glu-Tyr-Gly-Ca was slightly damaged in the intestinal fluid and at different temperatures, whereas it was severely damaged in the gastric fluid and acidic conditions. The results of the calcium dialysis percentage and Caco-2 cells experiments showed that Glu-Tyr-Gly-Ca possessed good calcium transport activity and bioavailability. The findings provided theoretical basis for Glu-Tyr-Gly-Ca as potential calcium supplement to improve intestinal calcium absorption.

Degradation of chondroitin sulfate: Mechanism of degradation, influence factors, structure-bioactivity relationship and application.

Increasing studies focus on chondroitin sulfate (CS) degradation to improve its biological activity. The review mainly introduces the degradation methods of CS and their mechanisms. Studies have shown that different degradation methods can lead to different structures of low molecular weight chondroitin sulfate (LMCS). LMCS were prepared through ß-elimination reaction, hydrolysis reaction, hydrogen abstraction reaction, and deamination reaction. The degradation of CS is affected by two aspects: the structure of CS (disaccharide composition and molecular weight) and the influence of degradation conditions (temperature, pH, degradation promoters, auxiliary conditions, and time). LMCS with different structures have different biological activities. In addition, degradation could also change CS's metabolism, such as absorption effects and gut microbiota. Thus, choosing the appropriate degradation method for CS development and utilization is very important.

Preparation of a cattle bone collagen peptide-calcium chelate by the ultrasound method and its structural characterization, stability analysis, and bioactivity on MC3T3-E1 cells.

This study was designed to prepare a cattle bone-derived collagen peptide-calcium chelate by the ultrasound method (CP-Ca-US), and its structure, stability, and bioactivity on MC3T3-E1 cells were characterized. Single-factor experiments optimized the preparation conditions: ultrasound power 90 W, ultrasound time 40 min, CaCl2/peptides ratio 1/2, pH 7. Under these conditions, the calcium-chelating ability reached 39.48 µg mg-1. The result of Fourier transform-infrared spectroscopy indicated that carboxyl oxygen and amino nitrogen atoms were chelation sites. Morphological analysis indicated that CP-Ca-US was characterized by a porous surface and large particles. Stability analysis demonstrated that CP-Ca-US was stable in the thermal environment and under intestinal digestion. CP-Ca-US showed more stability in gastric juice than the chelate prepared by the hydrothermal method. Cell experiments indicated that CP-Ca-US increased osteoblast proliferation (proliferation rate 153% at a concentration of 300 µg mL-1) and altered the cell cycle. Significantly, CP-Ca-US enhanced calcium absorption by interacting with calcium-sensing receptors and promoted the mineralization of MC3T3-E1 cells. This study provides the scientific basis for applying the ultrasound method to prepare peptide-calcium chelates and clarifies the positive role of chelates in bone building.

Comparative Analysis of the Bioactive Compounds in Chicken Cartilage: Protective Effects of Chondroitin Sulfate and Type II Collagen Peptides Against Osteoarthritis Involve Gut Microbiota.

This study was designed to explore osteoarthritis (OA) treatment from bioactive compounds of chicken cartilage food supplements. The OA rat model induced by sodium iodoacetate was used to evaluate the treatment effect in vivo. In this study, we used animal experiments to show that oral chondroitin sulfate (CS), cartilage powder, and type II collagen peptides could increase the athletic ability of rats and reduce inflammatory cytokine levels in serum or synovial fluid, including prostaglandin E2, tumor necrosis factor-α, interleukin (IL) 1ß, IL-6, and IL-17. CS displayed the best treatment effect against OA. The morphological structure of articular cartilage indicated that CS could significantly improve cartilage tissue morphology and reduce OA score. Oral CS slowed down the development of OA by modulating gut microbiota. These results provided a useful scientific basis for the high-value utilization of chicken cartilage.