The role of adhesion molecules in osteocalcin-induced effects on glucose and lipid metabolism in adipocytes.

Recent findings suggest that uncarboxylated osteocalcin (GluOC) promotes glucose and lipid metabolism via its putative receptor GPRC6A; however, its direct effect on adipocytes remains elusive. In this study, we elucidated the effects of GluOC on adipocytes, with an emphasis on the role of cell adhesion molecules. We determined that GluOC promoted the expression of adipocyte adhesion molecule (ACAM) and its transcription factor Krüppel-like factor 4 and enhanced the cortical actin filament assembly, which ameliorated lipid droplet hypertrophy. Additionally, GluOC upregulated the expression of integrin αVß3 and activation of focal adhesion kinase (FAK) and prevented insulin receptor substrate 1 (IRS1) degradation by inhibiting the ubiquitin-proteasome system via the FAK-PLC-PKC axis, which activated IRS1-Akt-mediated glucose transporter 4 (GLUT4) transport. Furthermore, we showed that GluOC elevated the expression of the insulin-independent glucose transporters GLUT1 and GLUT8, which facilitated insulin stimulation-independent glucose transport. The GluOC-induced activation of integrin αVß3 signaling promoted microtubule assembly, which improved glucose and lipid metabolism via its involvement in intracellular vesicular transport. GluOC treatment also suppressed collagen type 1 formation, which might prevent adipose tissue fibrosis in obese individuals. Overall, our results imply that GluOC promotes glucose and lipid metabolism via ACAM, integrin αVß3, and GLUT1 and 8 expression, directly affecting adipocytes.

Osteocalcin activates lipophagy via the ADPN-AMPK/PPARα-mTOR signaling pathway in chicken embryonic hepatocyte.

Fatty liver hemorrhage syndrome (FLHS) is the leading cause of noninfectious mortality in caged layers worldwide. Osteocalcin (OCN) is a protein secreted by osteoblasts, and its undercarboxylated form (ucOCN) acts as a multifunctional hormone that protects laying hens from FLHS. Lipophagy is a form of selective autophagy that breaks down lipid droplets (LDs) through lysosomes, and defective lipophagy is associated with FLHS. The aim of this study was to investigate the effects of ucOCN on the lipophagy of chicken embryonic hepatocytes and associated the function of the adiponectin (ADPN) signaling pathway. In this study, chicken embryonic hepatocytes were divided into 5 groups: control (CONT), fat emulsion (FE, 10% FE, v/v), FE with ucOCN at 1 ng/mL (FE-LOCN), 3 ng/mL (FE-MOCN), and 9 ng/mL (FE-HOCN). In addition, 4 µM AdipoRon, an adiponectin receptor agonist, was used to investigate the function of ADPN. The results showed that compared with CONT group, FE promoted the levels of phosphorylation of mammalian target of rapamycin (p-mTOR) (P < 0.05) and decreased the mRNA expression of ADNP receptors (AdipoR1 and AdipoR2). Compared with FE group, 3 and 9 ng/mL ucOCN inhibited the levels of autophagy adaptor p62 and p-mTOR (P < 0.05), increased the ratios of LC3-II/LC3-I (P < 0.05) and phosphorylated adenosine 5'-monophosphate-activated protein kinase (p-AMPK)/AMPK (P < 0.05), as well as the levels of peroxisome proliferator-activated receptor α (PPAR-α) and ADPN (P < 0.05). In addition, ucOCN at the tested concentrations increased the colocalization of LC3 and LDs in fatty hepatocytes. Administrated 4 µM AdipoRon activated AdipoR1 and AidpoR2 mRNA expression (P < 0.05), decreased the concentrations of triglyceride (P < 0.05), without effects on cell viability (P > 0.05). AdipoRon also increased the LC3-II/LC3-I ratio (P < 0.05) and the levels of p-AMPK/AMPK and PPAR-α (P < 0.05). In conclusion, the results reveal that ucOCN regulates lipid metabolism by activating lipophagy via the ADPN-AMPK/PPARα-mTOR signaling pathway in chicken embryonic hepatocytes. The results may provide new insights for controlling FLHS in laying hens.

In Vitro and In Vivo Bone-Forming Effect of a Low-Molecular-Weight Collagen Peptide.

This study reveals that low-molecular-weight collagen peptide (LMWCP) can stimulate the differentiation and the mineralization of MC3T3-E1 cells in vitro and attenuate the bone remodeling process in ovariectomized (OVX) Sprague-Dawley rats in vivo. Moreover, the assessed LMWCP increased the activity of alkaline phosphatase (ALP), synthesis of collagen, and mineralization in MC3T3-E1 cells. Additionally, mRNA levels of bone metabolism-related factors such as the collagen type I alpha 1 chain, osteocalcin (OCN), osterix, bone sialoprotein, and the Runt family-associated transcription factor 2 were increased in cells treated with 1,000 µg/ml of LMWCP. Furthermore, we demonstrated that critical bone morphometric parameters exhibited significant differences between the LMWCP (400 mg/kg)-receiving and vehicle-treated rat groups. Moreover, the expression of type I collagen and the activity of ALP were found to be higher in both the femur and lumbar vertebrae of OVX rats treated with LMWCP. Finally, the administration of LMWCP managed to alleviate osteogenic parameters such as the ALP activity and the levels of the bone alkaline phosphatase, the OCN, and the procollagen type 1 N-terminal propeptide in OVX rats. Thus, our findings suggest that LMWCP is a promising candidate for the development of food-based prevention strategies against osteoporosis.

Exercise ameliorates anxious behavior and promotes neuroprotection through osteocalcin in VCD-induced menopausal mice.

AIMS: As the ovaries age and women transition to menopause and postmenopause, reduced estradiol levels are associated with anxiety and depression. Exercise contributes to alleviate anxiety and depression and the bone-derived hormone osteocalcin has been reported to be necessary to prevent anxiety-like behaviors. The aim of this study was to investigate the effects of exercise on anxiety behaviors in climacteric mice and whether it was related to osteocalcin. METHODS: Menopausal mouse model was induced by intraperitoneal injection of 4-vinylcyclohexene diepoxide (VCD). Open field, elevated plus maze, and light-dark tests were used to detect anxious behavior in mice. The content of serum osteocalcin was measured and its correlation with anxiety behavior was analyzed. BRDU and NEUN co-localization cells were detected with immunofluorescence. Western blot was applied to obtain apoptosis-related proteins. RESULTS: The VCD mice showed obvious anxiety-like behaviors and 10 weeks of treadmill exercise significantly ameliorated the anxiety and increased circulating osteocalcin in VCD mice. Exercise increased the number of BRDU and NEUN co-localization cells in hippocampal dentate gyrus, reduced the number of impaired hippocampal neurons, inhibited the expression of BAX, cleaved Caspase3, and cleaved PARP, promoted the expression of BCL-2. Importantly, circulating osteocalcin levels were positively associated with the improvements of anxiety, the number of BRDU and NEUN co-localization cells in hippocampal dentate gyrus and negatively related to impaired hippocampal neurons. CONCLUSION: Exercise ameliorates anxiety behavior, promotes hippocampal dentate gyrus neurogenesis, and inhibits hippocampal cell apoptosis in VCD-induced menopausal mice. They are related to circulating osteocalcin, which are increased by exercise.

Impact of vitamin D supplementation on markers of bone turnover: Systematic review and meta-analysis of randomised controlled trials.

AIM: The effects of vitamin D administration on bone turnover markers (BTMs) in adults are controversial. Thus, we carried out a meta-analysis of available randomised controlled trials (RCTs) to examine the impact of vitamin D supplementation on BTMs. METHODS: To identify relevant RCTs, we searched the PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library and Embase databases for manuscripts published up to July 2022. The present study was conducted in agreement with the PRISMA guidelines. Weighed mean difference (WMD) and 95% confidence intervals (CI) were used to calculate the magnitude of the effect of the intervention. RESULTS: A total of 42 RCTs were included in the meta-analysis. The age of the participants enrolled in the RCTs ranged from 19.4 to 84 years. The pooled results depicted a decrease in deoxypyridinoline (DPD) concentrations (WMD: -1.58 nmol/mmol, 95% CI: -2.55, -.61, p = .001) following vitamin D supplementation. In addition, subgroup analyses demonstrated that vitamin D administration notably reduced procollagen type I N-terminal propeptide (PINP) levels in individuals aged >50 years and led to a pronounced decrease in alkaline phosphatase (ALP) values when the intervention lasted >12 weeks. No significant effect was observed on other BTMs, for example, collagen type 1 cross-linked C-telopeptide (CTX) and osteocalcin (OC) levels. CONCLUSION: Vitamin D administration decreases DPD, PINP and ALP levels, indicating a reduced bone turnover following the intervention. Other BTMs, for example, CTX or OC values, were not affected by vitamin D prescription. Vitamin D supplementation may exert a positive effect on some important BTMs.

Ginkgolide B facilitates muscle regeneration via rejuvenating osteocalcin-mediated bone-to-muscle modulation in aged mice.

BACKGROUND: The progressive deterioration of tissue-tissue crosstalk with aging causes a striking impairment of tissue homeostasis and functionality, particularly in the musculoskeletal system. Rejuvenation of the systemic and local milieu via interventions such as heterochronic parabiosis and exercise has been reported to improve musculoskeletal homeostasis in aged organisms. We have shown that Ginkgolide B (GB), a small molecule from Ginkgo biloba, improves bone homeostasis in aged mice by restoring local and systemic communication, implying a potential for maintaining skeletal muscle homeostasis and enhancing regeneration. In this study, we investigated the therapeutic efficacy of GB on skeletal muscle regeneration in aged mice. METHODS: Muscle injury models were established by barium chloride induction into the hind limb of 20-month-old mice (aged mice) and into C2C12-derived myotubes. Therapeutic efficacy of daily administrated GB (12 mg/kg body weight) and osteocalcin (50 µg/kg body weight) on muscle regeneration was assessed by histochemical staining, gene expression, flow cytometry, ex vivo muscle function test and rotarod test. RNA sequencing was used to explore the mechanism of GB on muscle regeneration, with subsequent in vitro and in vivo experiments validating these findings. RESULTS: GB administration in aged mice improved muscle regeneration (muscle mass, P = 0.0374; myofiber number/field, P = 0.0001; centre nucleus, embryonic myosin heavy chain-positive myofiber area, P = 0.0144), facilitated the recovery of muscle contractile properties (tetanic force, P = 0.0002; twitch force, P = 0.0005) and exercise performance (rotarod performance, P = 0.002), and reduced muscular fibrosis (collagen deposition, P < 0.0001) and inflammation (macrophage infiltration, P = 0.03). GB reversed the aging-related decrease in the expression of osteocalcin (P < 0.0001), an osteoblast-specific hormone, to promote muscle regeneration. Exogenous osteocalcin supplementation was sufficient to improve muscle regeneration (muscle mass, P = 0.0029; myofiber number/field, P < 0.0001), functional recovery (tetanic force, P = 0.0059; twitch force, P = 0.07; rotarod performance, P < 0.0001) and fibrosis (collagen deposition, P = 0.0316) in aged mice, without an increased risk of heterotopic ossification. CONCLUSIONS: GB treatment restored the bone-to-muscle endocrine axis to reverse aging-related declines in muscle regeneration and thus represents an innovative and practicable approach to managing muscle injuries. Our results revealed the critical and novel role of osteocalcin-GPRC6A-mediated bone-to-muscle communication in muscle regeneration, which provides a promising therapeutic avenue in functional muscle regeneration.

Morphological and biomechanical effects of vitamin K2 on fracture healing: An animal study on the rat tibia fracture model.

OBJECTIVE: The aim of this study was to evaluate the effects of vitamin K2 on fracture healing. METHODS: Twenty-four 6-week-old male Wistar albino rats that had open tibia fractures induced were included in this study. They were divided into 2 groups of 12, a group that had vitamin K2 administered over 30 consecutive days and a control group. After 30 days, the rats were sacrificed, and from each group, 6 tibiae were selected for biomechanical testing to examine the mechanical strength of the callus tissue using the Instron 3-point bending test and 6 tibiae were selected for histological analysis to examine the density and organization of callus tissue using Allen's grading system and Huo et al's grading system. Furthermore, weekly x-rays were taken to evaluate bone union described by Lane and Sandhu, and osteocalcin, procollagen I N-terminal propeptide, and procollagen I C-terminal propeptide were examined in blood samples taken by intracardiac puncture during sacrification. RESULTS: Breaking force (P = .047), breaking time (P = .019), stiffness (P = .039), fracture strength (P = .041), and Young's modulus (P = .032) showed a statistically significant increase in the K2 group. Procollagen I C-terminal propeptide (P = .024), procollagen I N-terminal propeptide (.047), and osteocalcin (.048) levels were significantly higher in the K2 group compared to the control group. Furthermore, 3rd-week x-rays showed higher bone union scores according to the Lane and Sandhu method in the K2 group (P = .014). However, the histological grading systems of Allen and Huo et al did not show statistically significant differences between groups (P = .086, P = .07, respectively). CONCLUSION: In light of these findings, it could be concluded that vitamin K2 has a significant positive effect on fracture healing.

Undercarboxylated osteocalcin and ibandronate combination ameliorates hindlimb immobilization-induced muscle wasting.

Immobilization leads to muscle wasting and insulin resistance, particularly during ageing. It has been suggested that undercarboxylated osteocalcin (ucOC) improves muscle mass and glucose metabolism. Bisphosphonates, an anti-osteoporosis treatment, might protect muscle wasting independent of ucOC. We hypothesize that the combination of ucOC and ibandronate (IBN) treatments has superior protective effects against immobilization-induced muscle wasting and insulin resistance than either treatment alone. C57BL/6J mice were hindlimb-immobilized for two weeks, with injections of vehicle, ucOC (90 ng/g daily) and/or IBN (2 µg/g weekly). Insulin/oral glucose tolerance tests (ITT/OGTT) were performed. Immediately after immobilization, muscles (extensor digitorum longus (EDL), soleus, tibialis anterior, gastrocnemius and quadriceps) were isolated and measured for muscle mass. Insulin-stimulated glucose uptake (EDL and soleus) was examined. Phosphorylation/expression of proteins in anabolic/catabolic pathways were examined in quadriceps. Primary human myotubes derived from older adult muscle biopsies were treated with ucOC and/or IBN, then signalling proteins were analysed. Combined treatment, but not individual treatments, significantly increased the muscle weight/body weight ratio in immobilized soleus (31.7%; P = 0.013) and quadriceps (20.0%; P = 0.0008) muscles, concomitant with elevated p-Akt (S473)/Akt ratio (P = 0.0047). Combined treatment also enhanced whole-body glucose tolerance (16.6%; P = 0.0011). In human myotubes, combined treatment stimulated greater activation of ERK1/2 (P = 0.0067 and 0.0072) and mTOR (P = 0.036), and led to a lesser expression of Fbx32 (P = 0.049) and MuRF1 (P = 0.048) than individual treatments. These findings suggest a potential therapeutic role for the ucOC and bisphosphonates combination in protecting against muscle wasting induced by immobilization and ageing. KEY POINTS: It has been suggested that undercarboxylated osteocalcin (ucOC) improves muscle mass and glucose metabolism. Bisphosphonates, an anti-osteoporosis treatment, might protect against muscle wasting independent of ucOC. The combination treatment of ucOC and ibandronate was shown to exert a greater therapeutic effect against immobilization-induced muscle wasting, and led to greater activation of anabolic pathway and less expression of catabolic signalling proteins in myotubes derived from older adults, compared with individual treatments. The combination treatment was found to improve whole-body glucose tolerance. Our findings suggest a potential therapeutic role for the ucOC and bisphosphonates combination in protecting against muscle wasting induced by immobilization and ageing.

Osteocalcin inhibits myocyte aging through promotion of starvation-induced autophagy via IL-6/STAT3 signaling.

This study aimed to investigate the effects and mechanisms of osteocalcin on autophagy in myoblasts, as well as its possible therapeutic effects in aging muscle. Starved murine myoblast C2C12 cells with or without interleukin (IL)-6 siRNA were treated with osteocalcin. Expression of the autophagy protein marker LC3, as well as IL-6 and phosphorylated STAT3 were detected by immunoblotting, immunofluorescence, or immunohistochemistry. Autophagosomes were observed with transmission electron microscopy. Levels of reactive oxygen species (ROS) were detected by flow cytometry. Fasted young mice were injected intraperitoneally with osteocalcin, with or without the JAK inhibitor CP-690550 to inhibit IL-6 signaling. Older mice were treated with osteocalcin and muscle mass, grip strength and muscle structure were assessed. The results revealed that compared to control and serum-starved cells, osteocalcin treatment significantly increased the relative expression of LC3-II/LC3-I protein, the numbers of autophagosomes, and levels of intracellular ROS. Osteocalcin injection in mice also resulted in increased relative LC3-II/LC3-I protein expression and autophagosome numbers. Osteocalcin treatment significantly increased the secretion of IL-6 in muscle cells and tissue, and activated STAT3 signaling. Moreover, knockdown of IL-6 or blocking IL-6 signaling inhibited the phosphorylation of STAT3, and further inhibited autophagy in starved myoblasts and fasting-treated murine muscle tissue. In addition, osteocalcin treatment significantly increased muscle mass and grip strength in both aged mice and aged fasting mice. In conclusion, the inhibition of osteocalcin on muscle cell aging is accompanied by the induction of IL-6-STAT3-dependent autophagy, indicating osteocalcin might be a promising therapeutic candidate for aging-related myopathies.

Impact of treatment with active vitamin D calcitriol on bone turnover markers in people with type 2 diabetes and stage 3 chronic kidney disease.

People with diabetes and chronic kidney disease (CKD) are predisposed to bone mineral disorders and increased fracture risk. There is limited data on the effect of calcitriol on bone turnover markers (BTMs) in people with type 2 diabetes (T2DM) and stage 3 CKD. In a pre-specified secondary endpoint analysis of a 48-week randomized placebo controlled double-blind trial, we studied the effects of oral calcitriol 0.25 µg once daily on circulating BTMs that included osteocalcin (OCN), C-terminal telopeptide of type I collagen (CTXI), procollagen type I N-propeptide (PINP) and fibroblast growth factor-23 (FGF-23). Inclusion criteria were people with T2DM with stable stage 3 CKD stage and intact parathyroid hormone (iPTH) >30 pg/ml. In total, 127 people [calcitriol (n = 64), placebo (n = 63)] were eligible for analyses. Baseline median (interquartile range) age of the cohort was 67 (60.5-70) years, iPTH (median range) 73.9 (55, 105) pg/ml and eGFR 40 (33, 48.5) ml/min. Calcitriol treatments resulted in a significant fall in iPTH, CTX, PINP and OCN levels and rise FGF-23, with mean (95 % confidence interval) between group differences in iPTH [-27.8 pg/ml; 95 % CI (-42.3 to -13.2); p < 0.001], FGF-23 [30.6 pg/ml; 95 % CI (14.8 to 46.3); p < 0.001], CTX [0.12 µg/l; 95 % CI (-0.19 to -0.06); (p < 0.001) and OCN [-4.03 ng/ml; 95 % CI (-7.8 to -0.27); p = 0.036]. Similarly we observed with calcitriol, as between treatment percentage change, a reduction of -38 % for iPTH, -34 % for CTX, and -28 % for OCN levels respectively (p < 0.05 for all). In people with T2DM and stage 3 CKD, calcitriol reduces the levels of CTX, OCN, PINP and iPTH. Further studies are needed to assess the clinical significance of our findings and the related long term impact on bone health.

[Study on promoting bone formation in osteoporotic zebrafish by lithium-doped hydroxyapatite nanowires].

PURPOSE: To observe the regulatory effect of lithium-doped hydroxyapatite nanowires on bone metabolism in osteoporotic zebrafish induced by dexamethasone. METHODS: Pure hydroxyapatite nanowires(nHA) and hydroxyapatite nanowires doped with 10% lithium ions (Li-nHA) were prepared by using hydrothermal method, and then material characterization was performed. The juvenile zebrafish cultured for 3 days(3dpf) were selected and co-cultured with nHA and Li-nHA extracts up to 7dpf. A negative(0.1% DMSO) control group was set up and transgenic zebrafish Tg(ola.sp7:nlsGFP) was used to select the best concentration for promoting bone formation. The osteoporotic zebrafish were induced by dexamethasone and incubated with nHA and Li-nHA extracts. The wild-type zebrafish was stained with alizarin red and the osteogenic differentiation was observed in transgenic zebrafish. Real-time quantitative PCR was adopted to detect osteogenic maker genes, such as zinc finger transcription factor (SP7), alkaline phosphatase (ALP), osteoprotegerin (OPG), Runt related transcription factor 2(Runx2) and osteocalcin (OCN). Statistical analysis was performed with GraphPad Prism 9.3 software. RESULTS: nHA and Li-nHA promoted bone formation and up-regulated expression levels of ALP, OCN, Runx2, SP7 and OPG of osteoporotic zebrafish. Compared with nHA, Li-nHA significantly increased the mineralization specific staining area and cumulative optical density of zebrafish bone, and the expression of osteogenic maker genes was also significantly increased. CONCLUSIONS: Doping lithium ions in nano hydroxyapatite can enhance its osteoinductive properties, and Li-nHA can effectively improve bone formation of osteoporotic zebrafish.

[Effect of miR-199a regulating IGF1 expression on differentiation of osteoblasts under mechanical stimulation].

PURPOSE: To investigate the expression change of microRNA (miR) - 199a in MC3T3-E1 cells stimulated by mechanical stretch and its mechanism of osteogenic differentiation. METHODS: MC3T3-E1 cells cultured in vitro were loaded with 12% stretch for 0, 3, 6, 12 and 24 hours, alkaline phosphatase (ALP) activity was detected by ALP activity test kit, the expressions of osteocalcin (OCN), osteoblast specific transcription factor osterix (OSX), Runt related transcription factor 2 (Runx2) mRNA and miR-199a were detected by real-time fluorescence quantitative PCR. MC3T3-E1 cells were divided into control group, stretch group, stretch + miR-NC group and stretch + miR-199a group, and the expressions of miR-199a, OCN, OSX, Runx2 mRNA and protein and ALP activity were observed after 12% stretch and transfection of miR-199a. Alizarin red S (ARS) staining was used to observe calcium nodule formation ability. The target relationship between miR-199a and insulin like growth factor-1 (IGF1) was detected by double luciferase reporter gene assay; in addition, the effect of miR-199a mimic on IGF1 mRNA and protein expression was detected by real-time fluorescent quantitative PCR and Western blot. SPSS 24.0 software package was used to analyze the data. RESULTS: Compared with those at the time point of 0 h, ALP activity and expression level of OCN, OSX and Runx2 mRNA of MC3T3-E1 cells at 3, 6, 12 and 24 hours after mechanical stretch stimulation were significantly higher, while the expression level of miR-199a was significantly lower(P＜0.05), and the change was most significant at 12 h. Compared with those in the control group, the expression level of miR-199a was significantly lower in the stretch group, while ALP activity, the expression level of OCN, OSX and Runx2 mRNA and protein, calcium nodule formation level were significantly high in the stretch group(P＜0.05); there was no significant difference in the above indexes between the stretch group and stretch + miR-NC group(P＞0.05). Compared with stretch + miR-NC group, the expression level of miR-199a in stretch + miR-199a group was significantly higher; while ALP activity, OCN, OSX, Runx2 mRNA and protein expression level, calcium nodule formation level were significantly lower(P＜0.05). miR-199a could targetedly bind to IGF1, and the expression level of IGF1 mRNA and protein in MC3T3-E1 cells was significantly reduced by miR-199a mimic(P＜0.05). CONCLUSIONS: MiR-199a can inhibit the osteogenic differentiation of MC3T3-E1 cells induced by mechanical stretch stimulation, and its mechanism may be related to the targeted regulation of IGF1 expression.

Osteocalcin reduces fat accumulation and inflammatory reaction by inhibiting ROS-JNK signal pathway in chicken embryonic hepatocytes.

Osteocalcin (OCN) has a function in preventing fatty liver hemorrhagic syndrome (FLHS) in poultry. The aim of this study was to investigate the effects of OCN on fat emulsion stimulated chicken embryonic hepatocytes and related signaling pathways. The primary chicken embryonic hepatocytes were isolated from the incubated 15-day (E15) pathogen free eggs and cultured with dulbecco's modified eagle medium (DMEM). After the hepatocyte density reached 80%, the cells were divided into 5 groups: control group (CONT), fat emulsion group (FE, 10% FE, v/v), FE with ucOCN at 1 ng/mL (FE-LOCN), 3 ng/mL (FE-MOCN), and 9 ng/mL (FE-HOCN). In addition, 2 mM N-Acetyl-L-cysteine (NAC) a reactive oxygen species (ROS) scavenger, and 5 µM SP600125, a Jun N-terminal kinase (JNK) inhibitor, were added separately in to the DMEM with 10% FE to test effects of FE on the function of ROS-JNK signal pathway. The number of hepatocytes, cell ultra-microstructure, viability, and apoptosis were detected after 48 h treatment, and the protein expressions and enzyme concentrations were detected after 72 h treatment. The results showed that, compared to the control group, FE increased the triglyceride (TG) concentration and lipid droplets (LDs) in chicken embryonic hepatocytes (P < 0.05), and induced hepatocytic edema with obviously mitochondrial swelling, membrane damage, and cristae rupture. FE also decreased ATP concentration, increased ROS concentrations and mitochondrial DNA (mtDNA) copy number, promoted inflammatory interleukin-1 (IL-1), IL-6, tumor necrosis factor-alpha (TNF-α) concentrations and hepatocytic apoptosis rate, and raised phospho-c-Jun N-terminal kinase (p-JNK) protein expressions. Compared to the FE group, ucOCN significantly increased hepatocyte viability, reduced hepatocytic TG concentrations and LDs numbers, and alleviated hepatocytic edema and mitochondrial swelling. Furthermore, ucOCN significantly decreased ROS concentrations, increased ATP concentrations, reduced IL-1, IL-6, TNF-α concentrations and hepatocytic apoptosis rate, and inhibited p-JNK protein expressions (P < 0.05). NAC had the similar functions of ucOCN reduced the ROS concentration and inhibited the TNF-α protein expression and p-JNK/JNK ration. Similarly, SP600125 reduced p-JNK/JNK protein expression, IL-1, IL-6, TNF-α, and TG concentrations without effects on ROS concentration and hepatocytic apoptosis. These results suggest that ucOCN alleviates FE-induced mitochondrial damage, cellular edema, and apoptosis of hepatocytes. These results reveal that the functions of ucOCN in reducing fat accumulation and inflammatory reaction in chicken embryonic hepatocytes are mostly via inhibiting the ROS-JNK signal pathway.

The effect of osteoporotic and non-osteoporotic individuals' T cell-derived exosomes on osteoblast cells' bone remodeling related genes expression and alkaline phosphatase activity.

OBJECTIVES: Osteoporosis is a common skeletal disorder attributed to age and is defined as a systematic degradation of bone mass and the microarchitecture leading to bone fractures. Exosomes have been reported in almost all biological fluids and during the failure of bone remodeling. 20 ml of blood samples were obtained from osteoporotic and non-osteoporotic postmenopausal women. After the isolation of peripheral blood mononuclear cells (PBMCs), T cells were separated via the magnetic-activated cell sorting (MACS) technique. Exosomes were driven from T cells of non-osteoporotic and osteoporotic volunteers. Subsequently, normal osteoblasts were treated with obtained T cell exosomes to assess osteoblastic function and gene expression. RESULTS: Runx2, type I collagen, osteopontin, and osteocalcin expression decreased in osteoblasts treated by osteoporotic T cell exosomes. In contrast, an increased expression of the mentioned genes was observed following non-osteoporotic T cell exosome treatment. Additionally, osteoblast alkaline phosphatase (ALP) activity treated with non-osteoporotic T cell exosomes increased. However, this activity decreased in another group. Our data demonstrated that T cell exosomes obtained from osteoporotic and non-osteoporotic individuals could alter the osteoblastic function and gene expression by affecting the genes essential for bone remodeling.

The Effect of the Angiotensin-Converting Enzyme Inhibitor on Bone Health in Castrated Hypertensive Rats Is Mediated via the Kinin-Kallikrein System.

Background: In previous studies, angiotensin-converting enzyme inhibitor (ACEI) use was associated with increased bone loss, while an angiotensin II type I receptor blocker had no effect on bone loss in elder subjects, which suggested that the effect of ACEI on bone loss was not mediated through the classical renin-angiotensin system. In this study, we set to investigate whether the effect of ACEI on bone deterioration was mediated via the kinin-kallikrein system. Methods: Six-month-old male and female spontaneously hypertensive rats were used. The effect of captopril on blood pressure, serum Ang II, and bradykinin concentration was measured in intact rats. Ovariectomy and orchidectomy were performed to establish an osteoporosis model in female and male rats, respectively. Captopril and the bradykinin receptor blocker icatibant (HOE140) were administered after operation for 12 weeks. Serum Ang II and bradykinin concentration, bone turnover markers, bone mineral density (BMD), and bone microarchitecture were evaluated. Femur samples were subjected to a mechanical test. Results: Captopril decreased blood pressure and serum Ang II concentration and increased serum bradykinin concentration in intact rats (P < 0.05). After castration, captopril decreased serum Ang II concentration (P < 0.05); in female rats, icatibant increased serum Ang II concentration (P < 0.05). Captopril increased serum bradykinin concentration (P < 0.05); in male rats, icatibant decreased serum bradykinin concentration (P < 0.05). Captopril increased the rat urine deoxypyridinoline-creatinine ratio (DPD/Cr) and serum osteocalcin concentration (P < 0.05). Icatibant decreased urine DPD/Cr in male rats (P < 0.05) and increased osteocalcin concentration in female rats (P < 0.05). Captopril increased cancellous BMD in castrated hypertensive rats (P < 0.05), and icatibant further increased cancellous BMD (P < 0.05), which was due to the increased trabecular bone number. In mechanical testing, ACEI increased bone strength (P < 0.05), and icatibant further improved it (P < 0.05). Conclusion: ACEI decreased bone deterioration in both male and female hypertensive rats, and the bradykinin receptor blocker further decreased bone deterioration.

Impact of hydrocortisone replacement on bone mineral density and bone turnover markers in patients with primary adrenal insufficiency.

Objective. The study was aimed to assess the effect of hydrocortisone (HC) replacement therapy on bone mineral density (BMD) and bone turnover markers in patients with primary adrenal insufficiency (PAI). METHODS: A cross-sectional study was conducted in 37 PAI patients treated with HC. BMD and selected bone turnover markers (ß-crosslaps and osteocalcin) were measured. A stepwise binary logistic regression model was applied to determine the independent variables associated with low BMD. RESULTS: Osteoporosis was noted in 14.3% and osteopenia in 34.3% of cases. These patients were older (p=0.01) and received higher daily HC dose compared to patients with normal BMD (p=0.01). BMD values in the lumbar spine and the femoral neck were negatively correlated with daily HC dose (r=-0.36, p=0.03 and r=-0.34, p=0.05, respectively). Plasma osteocalcin was negatively correlated with disease duration (r=-0.38, p=0.02) and cumulative HC dose (r=-0.43, p<0.01). In multivariate analysis, a daily HC dose ≥12 mg/m2/day was independently associated with a higher risk of osteopenia/osteoporosis [OR (95% CI), 9.0 (1.1-74.6); p=0.04]. CONCLUSIONS: Impaired bone mineralization in patients with PAI is correlated with HC dose. A daily HC dose ≥12 mg/m2/day was associated with an increased risk of osteopenia and osteoporosis in these patients.

Effects of Bisphosphonate on Osteocyte Proliferation and Bone Formation in Patients with Diabetic Osteoporosis.

Background: Bisphosphonate is currently considered one of the drugs for the first-line treatment of osteoporosis because of its ability to inhibit bone resorption, but the molecular mechanism of its effect on osteocyte proliferation and bone formation of diabetic osteoporosis is still unclear. Objective: To confirm the potential effect on of bisphosphonate on osteocyte proliferation and bone formation in patients having diabetic osteoporosis (DO). Methods: Sixty DO patients admitted to our hospital from February 2019 to April 2021 were randomly selected and divided into the bisphosphonate group and the control group. The total incidence, incidence of hip fracture, efficacy, bone mineral density, osteocalcin, pain score, osteocyte proliferation, bone formation index, serum calcium, and phosphorus contents were compared between two groups. Results: The curative effect of bisphosphonic acid group was better than that of control group, and the difference was statistically significant (P < 0.05). Compared with the control group, the bone mineral density and osteocalcin in the bisphosphonic acid group were significantly improved after treatment, and the pain score in the bisphosphonic acid group was significantly lower than that in the control group (P < 0.05). After intervention treatment, the OD and PINP values in the bisphosphonate group were significantly different from those in the control group (P < 0.05). After treatment, the contents of serum calcium and phosphorus in the bisphosphonic acid group were significantly higher than those in the control group (P < 0.05). The incidence of hip fracture, spinal fracture, and other fractures in the bisphosphonic acid group was significantly lower than that in the control group (P < 0.05). Conclusion: The treatment of DO with bisphosphonate is capability of effectively improving bone cell proliferation and bone formation, further alleviating clinical symptoms and promoting the improvement of the disease.

Impact of Sr2+ and hypoxia on 3D triple cultures of primary human osteoblasts, osteocytes and osteoclasts.

An in vitro bone triple culture involving human primary osteoblasts, osteocytes and osteoclasts enables the investigation of bone healing factors, drugs or biomaterials in a model system for native bone tissue. The present study analyses the impact of Sr2+ as well as hypoxic cultivation (5% O2 content or chemically induced by Co2+) on bone cells. The three cell types were cultivated together in the presence of 100 µM Sr2+, hypoxic conditions or in the presence of 75 µM Co2+. After cultivation the cell types were separated and analysed on mRNA and protein level individually. In response to Sr2+ osteoblasts showed a downregulation of IBSP expression and a stimulation of ALP activity. Osteocyte gene marker expression of PDPN, MEPE, RANKL, OPG, osteocalcin and likewise the amount of secreted osteocalcin was reduced in the presence of Sr2+. Activity of osteoclast-specific enzymes TRAP and CAII was enhanced compared to the Sr2+ free control. Hypoxic conditions induced by both 5% O2 or a Co2+ treatment led to decreased DNA content of all bone cells and downregulated expression of osteoblast markers ALPL and IBSP as well as osteocyte markers PDPN, RANKL and OPG. In addition, Co2+ induced hypoxia decreased gene and protein expression of osteocalcin in osteocytes. In response to the Co2+ treatment, the TRAP gene expression and activity was increased. This study is the first to analyse the effects of Sr2+ or hypoxia on triple cultures with primary human bone cells. The investigated in vitro bone model might be suitable to reduce animal experiments in early stages of biomaterial and drug development.

Meta-Analysis of Effects of Nutritional Intervention Combined with Calcium Carbonate D3 Tablets on Bone Mineral Density, Bone Metabolism, and Curative Effect in Patients with Osteoporosis.

To investigate the changes in bone mineral density, bone metabolism, and efficacy of nutritional intervention combined with calcium carbonate D3 tablets in patients with osteoporosis, a RevMan 5.2 software meta-analysis was conducted in this study. According to the therapeutic direction of nutritional intervention combined with calcium carbonate D3 tablets for osteoporosis patients, relevant literature were searched in Wanfang Medical, CNKI, VIP, and PubMed literature databases at home and abroad. Keywords included bone mineral density, bone metabolism, blood calcium (Ca), blood phosphorus (P), osteocalcin (OC), bone mineral density (BMD), serum alkaline phosphatase (ALP), efficacy, osteoporosis, and nutritional intervention. Literature that met the criteria were deleted, and meta-analysis was performed using RevMan 5.2 software. The results indicate that a total of 10 Chinese literature were included. Compared with the monotherapy group, the clinical efficacy, osteocalcin, BMD, alkaline phosphatase, calcium, and phosphorus were significantly higher in the combination group (P < 0.05). Based on calcium carbonate D3, treatment combined with nutritional intervention can enhance the clinical efficacy, bone metabolism, and bone mineral density of patients with osteoporosis, and nutritional intervention combined with calcium carbonate D3 tablets is a feasible program to promote the recovery of patients with osteoporosis.

Ponicidin Treatment Improved the Cell Proliferation, Differentiation, and Calcium Mineralization on the Osteoblast-Like MG-63 Cells.

Osteoporosis is a general bone-related ailment characterized by reduced bone density and quality, elevated bone fragility, and fractures. It was reported that both aged men and women has an increased risks of osteoporosis. The current research work focused to unveil the beneficial roles of ponicidin treatment in the proliferation and calcium deposition on the osteoblast-like MG-63 cells. The effect of 5 and 10 µg/ml of ponicidin on the cell proliferation was assessed. The viability of ponicidin-supplemented MG-63 cells was inspected by MTT test. The contents of osteocalcin, collagen, and ALP activity in the ponicidin administered cells were assessed by kits. The level of calcium mineralization was examined by ARS staining technique. The ponicidin treatment remarkably improved the proliferation of MG-63 cells. The ponicidin did not affect the MG-63 cells viability but promoted its viability 24- and 48-h treatment. The contents of osteocalcin, collagen, and ALP activity in the 5 and 10 µg/ml of ponicidin-supplemented MG-63 cells were found increased than the control cells. The ponicidin also increased the level of calcium deposition in MG-63 cells, which is assessed by ARS staining. In conclusion, it was clear that ponicidin improved the proliferation and calcium mineralization in a MG-63 cells. Therefore, it was clear that ponicidin has helpful roles on the new bone development as a hopeful therapeutic candidate to treat the bone-related disease like osteoporosis.