Activity Of Osteoblastic Cells Research Articles

Role of ginsenosides in bone remodelling: A narrative review on molecular mechanism

Osteoporosis (OP) is a metabolic bone disease that impacts a large number of humanity. Degeneration of the bone microstructure, loss of mass, and heightened fragility are symptoms. The primary reason is because the rates of bone formation and resorption are different. Extensive research on the effects of ginsenoside, a component of ginseng used in traditional Indian medicine, on osteoporosis has shown promising results. There were forty-four articles written about ginsenosides, osteoblasts, osteoclasts, osteoporosis, and bone mesenchymal cells. The effects of ginsenosides on osteoblast, osteoclast, and mesenchymal stem cell activity in bone remodelling and their potential role in preventing osteoporosis were the focus of these studies. This in-depth study sheds light on the several ginsenosides used to treat osteoporosis from different perspectives, paving the way for potential therapeutic applications in the future.

Biological activity of tantalum oxide coating doped with calcium and strontium by micro-arc oxidation under osteoimmunomodulation

Tantalum is widely used in clinics due to its excellent properties. However, its high density and elastic modulus constrain its application as a large implant. The new porous tantalum material addresses the issue of incompatibility between the implant and the human body. Nevertheless, it still exhibits biological inertia and limited bone-bonding ability; therefore, it is necessary to modify its surface. At present, some surface modification methods have inconsistent results in vitro and in vivo. To solve this problem, this study described the preparation of a ceramic coating with a "trabeculae-like" structure on the surface of pure tantalum using micro-arc oxidation (MAO). Calcium and strontium ions were introduced by adding acetate to the electrolyte. The effects of incorporating bioactive ions Ca2+ and Sr2+ into the electrolyte on the coating's morphology, coating thickness, phase composition, roughness, hydrophilicity, and the activity of MC3T3-E1 osteoblast cells under osteoimmunomodulation were investigated. The results demonstrated that the introduction of bioactive ions did not change the porous morphology of the coating; instead, it led to an increase in coating thickness, enhancement of surface roughness and hydrophilicity, as well as promotion of osteoblast spreading, proliferation, and ALP activity. Moreover, it regulated the phenotypic polarization of RAW264.7 macrophages to augment osteoblast proliferation, spreading, and ALP activity, implying that the coating has superior osteogenic potential under osteoimmunomodulation.

Human gingival mesenchymal stem cells-lyosecretome attenuates adverse effect of hydrogen peroxide-induced oxidative stress on osteoblast cells

ObjectiveTo determine total protein content, antioxidant activity, and protective ability of lyophilized human gingival mesenchymal stem cells (hGMSCs)-secretome in hydrogen peroxide (H2O2) induced oxidative stress model. MethodsHuman GMSCs were cultured to obtain a conditioned medium (secretome), then lyophilized to produce lyosecretome. Total protein was determined by bicinchoninic acid assay (BCA) and SDS-PAGE to improve protein measurements. Antioxidant concentration was measured by ABTS assay, while the protective ability of lyosecretome against oxidative stress was determined by the metabolic activity of osteoblast cells. The study group was divided into a control group (culture medium) and a lyosecretome treatment group (0.0; 0.157, 0.313, 0.625, 1.25, 2.5, 5, and 10 mg/mL + H2O2). ResultsLyosecretome had a protein concentration of 2086.00 ± 0.20 μg/ml, with a molecular weight of 174, 74, 61, 55, and 26 kDa, which are thought to facilitate cell migration, as well as bind cytokines and growth factors. Lyosecretome also provided the highest antioxidant activity of 93.51% at a concentration of 4.8 mg/ml, with an IC50 value of 2.08 mg/ml. The highest cell metabolic activity (79.53 ± 2.41%) was shown in the 1.25 mg/ml lyosecretome treatment group. All concentrations of hGMSC-lyosecretome attenuate the adverse effect of H2O2-induced oxidative stress. ConclusionLyosecretome obtained from hGMSCs can maintain metabolic activity in osteoblast cells as protection against H2O2 oxidative stress.

Water-soluble biopolymers calcium polymalate derived from fermentation broth of Aureobasidium pullulans markedly alleviates osteoporosis and fatigue

Osteoporosis is a prevalent condition characterized by bone loss and decreased skeletal strength, resulting in an elevated risk of fractures. Calcium plays a crucial role in preventing and managing osteoporosis. However, traditional calcium supplements have limited bioavailability, poor solubility, and adverse effects. In this study, we isolated a natural soluble biopolymer, calcium polymalate (PMACa), from the fermentation broth of the fungus Aureobasidium pullulans, to investigate its potential as an anti-osteoporosis therapeutic agent. Characterization revealed that linear PMA-Ca chains juxtaposed to form a porous, rod-like state, in the presence of Ca2+. In vivo mouse models demonstrated that PMA-Ca significantly promoted the conversion of serum calcium into bone calcium, and stimulated bone growth and osteogenesis. Additionally, PMA-Ca alleviated exercise fatigue in mice by facilitating the removal of essential metabolites, such as serum lactate (BLA) and blood urea nitrogen (BUN), from their bloodstream. In vitro studies further showed that PMA-Ca strengthened osteoblast cell activity, proliferation, and mineralization. And PMA-Ca upregulated the expression of some genes involved in osteoblast differentiation, indicating a potential correlation between bone formation and PMACa. These findings indicate that soluble PMA-Ca has the potential to be a novel biopolymer-based calcium supplement with sustainable production sourced from the fermentation industry.

Prevention of Osteoporotic Disorders with Foxtail Millet (Setaria Italica)

Objectives: 1. To review the effect of foxtail millet in Bone health. 2. To review Asthivikara according to Ayurvedic science. 3. To review about ayurvedic and modern concept of Foxtail Millet and Osteoporosis. Materials and methods: All the research work regarding foxtail millet, Osteoporosis, Bone health, Sandhankarma has been searched from science direct, PUBMED, scholar articles. Various classical text of ayurveda and modern science has been reviewed. Discussion: foxtail millet possesses Madhura (sweet), Astringent (Kashaya) rasa, Guru guna (heavy), ruchya property (increases taste), Sheeta veerya (cold potency), brumhana karma (nourishing), sandhankar (healing) property. It is rich in Vitamin B12, protein, good fat, carbs and dietary fibre content. Besides copious amounts of lysine, thiamine, iron and niacin, it also offers abundant amounts of calcium. Osteoporosis was first considered to be an age-related disorder characterized by low bone mass and increased bone fragility, thereby putting the patient at risk of fractures. Studies have reported an increased risk of developing osteoporosis in patients with various inflammatory conditions. Bound polyphenols of inner shell (BPIS) from foxtail millet bran can display anti-inflammatory effects Conclusion: Foxtail millet diet consumption will help in prevention of osteoclastic activity i.e. bone resorption process and may promote the activity of osteoblastic cells i.e. bone forming cells. It can promote anti-inflammatory effect. But according to Ayurveda, its consumption should be limited to once a day to prevent vitiation of Vata Dosha. So mass awareness and large scale research study is required for significant result.

Zinc Deficiency Promotes Calcification in Vascular Smooth Muscle Cells Independent of Alkaline Phosphatase Action and Partly Impacted by Pit1 Upregulation.

Inorganic phosphate (Pi) is a critical determinant of calcification, and its concentration is regulated by alkaline phosphatase (ALP) and Pit1. ALP is a key regulator of osteogenic calcification and acts by modulating local inorganic phosphate (Pi) concentrations through hydrolyzing pyrophosphate in the extracellular matrix (ECM). Pit1, a sodium-dependent phosphate transporter, regulates calcification via facilitating phosphate uptake within the cells. To investigate whether zinc differentially regulates osteoblastic and vascular calcifications, we examined ALP activity and Pit1 in osteoblastic and vascular smooth muscle cells (VSMCs). Our findings demonstrate that calcification in osteoblastic MC3T3-E1 cells is decreased via diminished ALP action under zinc deficiency. In contrast, zinc-deficiency-induced calcification in VSMCs is independent of ALP action, as demonstrated by very weak ALP activity and expression in calcified VSMCs. In zinc-deficient A7r5 VSMC, P accumulation increased with increasing Na phosphate concentration (3-7 mM) but not with β-GP treatment, which requires ALP activity to generate Pi. Ca deposition also increased with Na phosphate in a dose-dependent manner; in contrast, β-GP did not affect Ca deposition. In osteoblastic cells, Pit1 expression was not affected by zinc treatments. In contrast, Pit1 expression is highly upregulated in A7r5 VSMC under zinc deficiency. Using phosphonoformic acid, a competitive inhibitor of Pit1, we showed that calcification is inhibited in both A7r5 and MC3T3-E1 cells, indicating a requirement for Pit1 in both calcifications. Moreover, the downregulation of VSMC markers under zinc deficiency was restored by blocking Pit1. Taken together, our results imply that zinc-deficiency-induced calcification in VSMC is independent of ALP action in contrast to osteoblastic calcification. Moreover, Pit1 expression in VSMCs is a target for zinc deficiency and may mediate the inhibition of VSMC marker expression under zinc deficiency.

The Impact of the Nasal Mucosal Flap on Tissue Remodeling After Sinus Bone Drilling in Rabbit Models.

Frontal sinus surgery remained a challenge of restenosis or obliteration of the drainage pathway caused by the scarring and neo-osteogenesis after mucosal stripping and bone drill-out. The pedicled or free nasal mucosal flap is typically used to repair the exposed bone surface to avoid or reduce recurrence. This study aimed to explore the histopathological mechanism of mucosal flaps repairing bare bone after mucosal resection and bone drill-out in the rabbit model. Thirty New Zealand white rabbits were used. Sixteen rabbits were selected as the experimental group, and Staphylococcus aureus was used to establish the CRS model (CRS group). Fourteen healthy rabbits were allocated to the control group (NCRS group). Each group was divided into two subgroups with or without mucosal flap repair (CRS-FLAP, CRS-NFLAP, NCRS-FLAP, and NCRS-NFLAP, respectively). The bony anterior and lateral walls of the maxillary sinus of each rabbit were abraded by the drill. The bare bone was then covered with a flap in FLAP subgroups. Bone remodeling and mucosal morphological changes were observed and compared by histopathological hematoxylin and eosin and Masson staining. In the CRS-NFLAP subgroup, the regenerated epithelium lacked typical structure, accompanied by numerous inflammatory cell infiltration and collagen deposition. Conversely, the inflammatory reaction was mild in the CRS-FLAP subgroup, and there was less collagen deposition. The restored mucosal structure was like the normal mucosa. The epithelium in the NCRS-NFLAP subgroup was partially exfoliated, with few cilia, goblet cells, and glandular structures. Compared with the NCRS-NFLAP subgroup, the CRS-NFLAP subgroup showed significant bone remodeling with enhanced activity of osteoblast and osteoclast cells. Pedicled mucosal flap repair could significantly reduce local mucosal and bone remodeling in a rabbit model of CRS.

MENINGIOMA-02 A RADIOLOGY- PATHOLOGICAL CORRELATION OF HYPEROSTOSIS AMONG PATIENTS WITH INTRACRANIAL MENINGIOMAS AT THE KENYATTA NATIONAL HOSPITAL.

Abstract BACKGROUND Meningiomas account for 34.4% of all central nervous system (CNS) neoplasms in Kenya. Hyperostosis has been described in 25% to 44% of meningiomas. According to Simpson et al, complete bony removal is associated with a 9% recurrence rate over a ten year period. Prior traumatic injury, activation of osteoblastic cells, synthesis of bone fragments and vascular abnormalities brought on by the neoplasm are all factors that may contribute to hyperostosis. The purpose of this study was to ascertain whether hyperostosis in cases of meningiomas are solely attributed to tumor invasion. MATERIALS AND METHODS This prospective study included all patients with a diagnosis of meningioma with radiological evidence of hyperostosis. Preoperatively, a computed tomography (CT) scan was done by a consultant radiologist in all patients and reviewed by two neurosurgeons for associated bony hyperostosis. Intra-op, a sample of the bone measuring 2cm by 2cm by 2cm displaying features of hyperostosis was harvested. Bone samples were decalcified with 10% formic acid. A consultant neuropathologist thereafter microscopically evaluated the samples to check for bone invasion. RESULTS Radiological evidence of hyperostosis was present in 22 (61.1%) patients out of 36 patients. Out of the 22 patients, female patients were 17(77.3%) while male patients were 5(22.7%). The median age of the patients at the time of surgery was 45.5 years (range 20-65 years; mean 44.3 ± 11.9 years). On histopathological examination, Meningothelial meningioma was the most common variant (59%). Microscopic tumor invasion of the bone was seen in 13 (59.1%) patients. CONCLUSION A significant number of patients with radiological hyperostosis had tumor invasion of the bone. The findings of this study show that one should remove the bone flap whenever possible in order to achieve total excision of the tumor, reduce recurrence rates and perform titanium mesh/ hydroxypartite cement cranioplasty for calvarial reconstruction.

Active nanoceramic compound dipped in biopolymers to create composite coating for metallic implant surface

Biofunctionalization of an implant using functional ceramics with exceptional electrical characterization, such as BaTiO3 and SrTiO3, has gained considerable attention in creating a composite coating with bio-polymer to activate metal implant surfaces for bone tissue engineering applications and, at the same time, resist bacterial infection. A Ti–Zr alloy sample was created by powder technology, and then a coating was applied using the electrospinning technique. Individually, nanopowders of ceramic compounds such as nBaTiO3 and nSrTiO3 were added to a blend of polycaprolactone and chitosan to create composite solutions that could be converted into a nanofibrous coating layer using the electrospinning technique. The samples were analyzed for their morphology, chemical composition, surface roughness, dielectric constant, and wettability. The techniques employed were SEM, EDS, FTIR, an LCR meter, and a contact angle goniometer. The samples' cytocompatibility was assessed by examining the cell viability, ALP activity, proliferation, and attachment of MC3T3-E1 osteoblast cells on both coated and uncoated sample surfaces.The bacterial resistance assays were conducted against Staphylococcus aureus and Streptococcus mutans. The findings demonstrate a notable enhancement in the biocompatibility of the coated specimens following a week of cellular cultivation. The composite coating containing piezoelectric BaTiO3 has a dielectric constant Ɛr (16) close to dry human bone at 100HZ frequency. Cell proliferation increases dramatically with time in coated samples, and the improvement approaches 125.16% for (BA1) and 111.38% for (SR1) as compared to uncoated Ti–25Zr sample. Cell viability percentage for the coated samples is compared with bare Ti–25Zr, which has an 80.52 ± 1.97% crucial increase, while (BA1) has 181.63 ± 17.87 and (SR1) 170.09 ± 18.12%. No zone of inhibition was detected in the bacterial resistance test for the uncoated sample, while the samples with composite coating show an adequate and comparable inhibitory zone. The composite nano-fiber has a strong biocompatibility, and the coating process is simple and economical, holding potential for use in orthodontic and orthopedic bone regeneration applications.

Surface polishing and modification of Ti-6Al-4V alloy by shear thickening polishing

In this study, a comparison of three newly developed polishing techniques namely, shear thickening polishing (STP), Chemistry enhanced STP (C-STP) and Electrolysis enhanced STP (E-STP) was made to investigate their suitability to Ti-6Al-4V biomaterials polishing and modification, which can produce Beilby layer after polishing and enhance mechanical and biological performance. The surface roughness Sa after STP was about 13.8 nm with a material removal rate of 54.3 nm/min. The C-STP showed the lowest surface roughness of 7.2 nm which was almost half that of STP and the MRR during C-STP was almost 2.1 times that of the conventional STP. The STP did not lead to any change of the surface composition, whereas a 136 nm thick Beilby layer was observed to form during the C-STP which revealed a lower friction coefficient of 0.04 as well as improved osteoblast cell activity. The E-STP showed an intermittent improvement as it provided a surface roughness of 10.2 nm and 1.6 times MRR than that obtained from conventional STP. Due to the dense oxide film of about 60 nm, the E-STP processed surface showed the best wettability and corrosion resistance. Overall, we reveal an important pathway for achieving scalable finishing on Ti-6Al-4V with desirable surface characteristics.

澱粉補強リン酸カルシウム骨ペーストへの異種カチオン種の導入

Bone cement is applied to bone detect caused by injury and disease. Our group has developed a novel bone paste by kneading a gelatinized wheat starch and calcium phosphate (CP) powders in which CaHPO4, Ca4(PO4)2O and β-Ca3(PO4)2 are equimolarly mixed. This bone paste is easily handled and can be set to form hydroxyapatite (HAp) under physiological conditions. On the other hand, previous literature reported that strontium ion can promote and regulate the activity of osteoblastic and osteoclastic cells in the living bone, respectively. In addition, copper ion is reported antibacterial performance. In this work, strontium and copper ions were fed into the bone paste as starting materials to promote cell activity as well as antibacterial properties. Paste samples were prepared by kneading a starch gelatinized with mixed powders of CP, α-SrHPO4 and Cu2+-substituted β-Ca3(PO4)2. Phase change, release behavior of metal cations and antibacterial properties were investigated. A paste sample immersed in Tris-buffered NaCl solution was set through forming HAp, and the amount of strontium ion released from the paste sample was a level expected to enhance the cell activity. However, all the pastes didn’t show antibacterial properties in spite of introducing of copper ion to the samples.

Low concentrations of grape seed extract maintain osteoblast morphology, cell adhesion, and mineralization.

The increase in life expectancy has led to a higher incidence of osteoporosis, characterized by an imbalance in bone remodeling. Several drugs are used for its treatment, but most promote undesirable side effects. The present investigation evaluated the effects of two low concentrations of grape seed extract (GSE) rich in proanthocyanidins on MC3T3-E1 osteoblastic cells. The cells were cultured in an osteogenic medium and divided into control (C), 0.1 µg/mL GSE (GSE0.1), and 1.0 µg/mL GSE (GSE1.0) groups to evaluate cell morphology, adhesion, and proliferation, in situ alkaline phosphatase (ALP) detection, mineralization and immunolocalization of osteopontin (OPN). The data obtained were analyzed by statistical tests for a significance of 5%. Cell morphology was maintained with both GSE concentrations, whereas cell adhesion significantly increased within three days in all groups. Cell proliferation increased significantly at seven days of culture, followed by a significant decrease in all experimental periods, with no statistical difference among them. In situ detection of ALP and mineralization increased with time, but within each period, no statistical differences among groups were observed. The expression of osteopontin was distributed regularly with more intensity after 24 hours in the GSE0.1 group. After three days, OPN expression was more intense in the control group, followed by GSE0.1 and GSE1.0 groups. Data obtained suggest that low concentrations of GSE do not affect the morphology and may stimulate the functional activity of osteoblastic cells.

JAW BONES MICROARCHITECTONICS AND MORPHOLOGY IN PATIENTS WITH DIABETES MELLITUS

The study, while aiming to study the microarchitectonics and morphology of the mandible alveolar part at dentition defects in 24 males (aged – 50-65; with type 2 diabetes mellitus going through the compensation stage following the correction of bone remodeling imbalance), and 19 healthy persons belonging to the same age group, implied analyzing 3D cross-sections of the adentia zone (through cone-beam computed tomograms), along with bone tissue biopsy histological examination, obtained from the projection area of dental implants. All patients had their biochemical features of bone metabolism within the reference values, the volume of the bone tissue at the missing teeth area was classified as Category A and B (by C.E. Mich, K.B.M. Judy, 1987), while the densitometry value at the lumbar spine and femoral neck (based on T-criterion) fell within the normal value (> -1SD). The X-ray and histological studies carried out in the studied groups, identified no significant differences in the quantitative and qualitative parameters of the mandibular alveolar part within the area of missing teeth. The morphology of the lower jaws alveolar part at the adentia area in healthy patients, which was represented by strongly interconnected trabeculae, single elements of adipose tissue in peritrabecular spaces, small resorption lacunae on the beam surface, few bonding lines, a depleted pool of osteogenic cells observed in the endossal layer – all these point at an age-related decrease in the intensity of reparation processes, as well as at a decreasing rate of bone tissue remodeling and development. The histological specifics of the mandibular alveolar part at the dentition defects in patients with type 2 diabetes, after pharmacological correction of the bone remodeling imbalance by way of interconnected trabeculae, local elements of adipose tissue against red bone marrow, a significant number of activated osteoblasts and inactive flattened osteogenic cell elements, enhanced activity of osteoblastic differon cells, as well as zones of the developing weakly mineralized osteoid, serve proof to an increase in the intensity of bone tissue metabolic processes, the predominance of the bone development phase over resorption and active osteogenesis. The results of X-ray and morphological studies show that in order to bring bone remodeling back to normal and reduce the risk of postoperative complications at the dental implantation in patients with compensated type 2 diabetes prior to dental rehabilitation, a good choice would imply carrying out pathogenetic pharmacological correction using groups of drugs capable of reducing bone resorption and enhancing bone development.

Organic Bone Matrix Component Type I and V Collagen Are Not Destructed in Bisphosphonate-Associated Osteonecrosis of the Jaws.

Background and objectives: The investigation of the pathophysiology behind medication-related osteonecrosis (MRONJ) of the jaw mostly focuses on alterations in osteoclast and osteoblast cell activity, but changes in the organic and inorganic bone matrix have rarely been studied. The aim of this study was to investigate whether collagen, the main organic component of extracellular bone matrix, is destructed in osteonecrosis of the jaw secondary to antiresorptive medication. Material and methods: Bone samples of patients with MRONJ (n = 15, control group n = 3) were demineralized, and collagen fragments were separated from intact collagen pellets by ultrafiltration. The quantification of mature collagen cross-links hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) in pellets and ultrafiltrates was performed by high-performance liquid chromatography (HPLC). The detection of hydroxyproline (Hyp) was carried out using a spectrophotometric assay. In addition, collagen chains were analyzed by sodium dodecylsulfate-polyacrylamide gel (SDS-PAGE). Results: The results revealed significantly higher concentrations of HP, LP and Hyp in pellet samples. In addition, there were no significant differences between samples from MRONJ patients and those of the control group. These results were paralleled by SDS- PAGE. Conclusion: These findings suggest that MRONJ does not involve the destruction of type I and V collagen molecules, in contrast to previously reported destruction by osteoradionecrosis.

In vitro model to study confined osteocyte networks exposed to flow-induced mechanical stimuli

Osteocytes are considered the primary mechanical sensor in bone tissue and orchestrate the coupled bone remodeling activity of adjacent osteoblast and osteoclast cells. In vivo investigation of mechanically induced signal propagation through networks of interconnected osteocytes is confounded by their confinement within the mineralized bone matrix, which cannot be modeled in conventional culture systems. In this study, we developed a new model that mimics this in vivo confinement using gelatin methacrylate (GelMA) hydrogel or GelMA mineralized using osteoblast-like model cells. This model also enables real-time optical examination of osteocyte calcium (Ca2+) signaling dynamics in response to fluid shear stimuli cultured under confined conditions. Using this system, we discovered several distinct and previously undescribed patterns of Ca2+ responses that vary across networks of interconnected osteocytes as a function of space, time and connectivity. Heterogeneity in Ca2+ signaling may provide new insights into bone remodeling in response to mechanical loading. Overall, such a model can be extended to study signaling dynamics within cell networks exposed to flow-induced mechanical stimuli under confined conditions.

Influence of melatonin associated with the Bio-Gide® membrane on osteoblast activity: an in vitro Study.

Melatonin (MLT) is a hormone responsible for regulating several physiological processes. It has been shown that MLT can be an important mediator in bone formation and stimulation, promoting osteoblast differentiation. In clinical practice, in tissue regeneration procedures, it is necessary to use membranes or barriers, associated with biomaterials, or not. The aim of this in vitro study was to assess the effect of melatonin on the activity of osteoblastic cells, associated, or not, with a resorbable collagen membrane (Bio-Gideä). For this, mice-derived pre-osteoblastic cells MC3T3 obtained from the ATCC (American Type Culture Collection) were used. Cultured cells were subject to the following treatments: MLT with a concentration of 1mM, a Bio-Gideä membrane and a membrane associated with MLT (Bio-Gideä + MLT). Proliferation and cell viability assays and protein lysate (ELISA test) quantification for the BMP-2 protein were carried out, in periods of 72 hours, 7 days and 10 days. After analyzing the data (one-way ANOVA, alpha=5%) it was observed that when MLT was used in isolation, there was an increase in cell proliferation and viability in osteoblastic cells (p<0.05). But, when MLT was associated with resorbable membranes, there was an inverse behavior, both in terms of proliferation and viability (p<0.05). In the case of the ELISA test, no secretion of BMP-2 was detected in any of the analyzed groups. It is concluded that MLT has a stimulatory effect on osteoblasts, but, when associated with Bio-Gideä resorbable membranes, it does not show any viable action in osteoblastic cell stimulation.

Effects of heat treatment of various pure metals on osteoblast cell activity

Effects of heat treatment of various pure metals on osteoblast cell activity

Maternal high-cholesterol diet negatively programs offspring bone development and downregulates hedgehog signaling in osteoblasts

Cholesterol is one of the essential intrauterine factors required for fetal growth and development. Maternal high cholesterol levels are known to be detrimental for offspring health. However, its long-term effect on offspring skeletal development remains to be elucidated. We performed our studies in two strains of mice (C57BL6/J and Swiss Albino) and human subjects (65 mother–female newborn dyads) to understand the regulation of offspring skeletal growth by maternal high cholesterol. We found that mice offspring from high-cholesterol-fed dams had low birth weight, smaller body length, and delayed skeletal ossification at the E18.5 embryonic stage. Moreover, we observed that the offspring did not recover from the reduced skeletal mass and exhibited a low bone mass phenotype throughout their life. We attributed this effect to reduced osteoblast cell activity with a concomitant increase in the osteoclast cell population. Our investigation of the molecular mechanism revealed that offspring from high-cholesterol-fed dams had a decrease in the expression of ligands and proteins involved in hedgehog signaling. Further, our cross-sectional study of human subjects showed a significant inverse correlation between maternal blood cholesterol levels and cord blood bone formation markers. Moreover, the bone formation markers were significantly lower in the female newborns of hypercholesterolemic mothers compared with mothers with normal cholesterolemic levels. Together, our results suggest that maternal high cholesterol levels deleteriously program offspring bone mass and bone quality and downregulate the hedgehog signaling pathway in their osteoblasts.

Alkaline Phosphatase Electrochemical Micro-Sensor Based on 3D Graphene Networks for the Monitoring of Osteoblast Activity.

Alkaline phosphatase (ALP) is a significant biomarker that indicates osteoblast activity and skeletal growth. Efficient ALP detection methods are essential in drug development and clinical diagnosis. In this work, we developed an in-situ synthesized three-dimensional graphene networks (3DGNs)-based electrochemical sensor to determine ALP activity. The sensor employs an ALP enzymatic conversion of non-electroactive substrate to electroactive product and presents the ALP activity as an electrochemical signal. With 3DGNs as the catalyst and signal amplifier, a sample consumption of 5 μL and an incubation time of 2 min are enough for the sensor to detect a wide ALP activity range from 10 to 10,000 U/L, with a limit of detection of 5.70 U/L. This facile fabricated sensor provides a quick response, cost-effective and non-destructive approach for monitoring living adherent osteoblast cell activity and holds promise for ALP quantification in other biological systems and clinical samples.

Stimulation of Metabolic Activity and Cell Differentiation in Osteoblastic and Human Mesenchymal Stem Cells by a Nanohydroxyapatite Paste Bone Graft Substitute.

Advances in nanotechnology have been exploited to develop new biomaterials including nanocrystalline hydroxyapatite (nHA) with physical properties close to those of natural bone mineral. While clinical data are encouraging, relatively little is understood regarding bone cells’ interactions with synthetic graft substitutes based on this technology. The aim of this research was therefore to investigate the in vitro response of both osteoblast cell lines and primary osteoblasts to an nHA paste. Cellular metabolic activity was assessed using the cell viability reagent PrestoBlue and quantitative, real-time PCR was used to determine gene expression related to osteogenic differentiation. A potential role of calcium-sensing receptor (CaSR) in the response of osteoblastic cells to nHA was also investigated. Indirect contact of the nHA paste with human osteoblastic cells (Saos-2, MG63, primary osteoblasts) and human bone marrow-derived mesenchymal stem cells enhanced the cell metabolic activity. The nHA paste also stimulated gene expression of runt-related transcription factor 2, collagen 1, alkaline phosphatase, and osteocalcin, thereby indicating an osteogenic response. CaSR was not involved in nHA paste-induced increases in cellular metabolic activity. This investigation demonstrated that the nHA paste has osteogenic properties that contribute to clinical efficacy when employed as an injectable bone graft substitute.