Levels Of Alkaline Phosphatase Activity Research Articles

Effects of porcine bone marrow-derived platelet-rich plasma on bone marrow-derived mesenchymal stem cells and endothelial progenitor cells

This study investigated the abundance of pro-regenerative growth factors in bone marrow-derived platelet-rich plasma (BM-PRP) and their effects on bone marrow-derived mesenchymal stem cells (BM-MSC) and bone marrow-derived endothelial progenitor cells (BM-EPC). Four 4–5 months-old domestic pigs were included, and each underwent bone marrow aspiration from its humerus bones and processed into bone marrow aspiration concentrate (BMAC) samples. The plasma and cellular portions of BMAC were subsequently separated and collected. The concentration of growth factors including BMP-2, PDGF-BB, TGF-β1 and VEGF in the plasma portion was measured and compared between BM-PRP and bone marrow-derived platelet-poor plasma (BM-PPP). It was found that platelet count was significantly higher in BM-PRP than in BM-PPP, but the concentration of above-mentioned growth factors was not significantly different between BM-PRP and BM-PPP. As most existing literature has indicated the regenerative potency of PRP, this study focused on assessing the effect of BM-PRP treatment on BM-MSC and BM-EPC proliferation, osteogenic differentiation and angiogenesis capacity by comparing samples with 2.5% BM-PRP treatment and samples without BM-PRP treatment (control). In response to BM-PRP treatment, the cellular doubling time increased with culturing time and was significantly shorter in the BM-PRP-treated samples than in control samples. For osteogenic differentiation, BM-PRP-treated BM-MSCs demonstrated a time-dependent increase in alkaline phosphatase (ALP) activity and expression levels of osteogenic differentiation markers. For the expression of angiogenic genes, none of the differences reached statistical significance despite a tendency of stronger expression at day 18 in BM-PRP-treated BM-EPCs. In conclusion, this in vitro study suggests that most BMP-2, PDGF-BB, TGF-β1 and VEGF-A contained in BM-PRP are not platelet-released and BM-PRP may have some stimulation (less than 1-fold) for MSC, EPC proliferation and MSC osteogenic differentiation.

Effect of Inducible BMP-7 Expression on the Osteogenic Differentiation of Human Dental Pulp Stem Cells.

BMP-7 has shown inductive potential for in vitro osteogenic differentiation of mesenchymal stem cells, which are an ideal resource for regenerative medicine. Externally applied, recombinant BMP-7 was able to induce the osteogenic differentiation of DPSCs but based on our previous results with BMP-2, we aimed to study the effect of the tetracyclin-inducible BMP-7 expression on these cells. DPSC, mock, and DPSC-BMP-7 cell lines were cultured in the presence or absence of doxycycline, then alkaline phosphatase (ALP) activity, mineralization, and mRNA levels of different osteogenic marker genes were measured. In the DPSC-BMP-7 cell line, the level of BMP-7 mRNA significantly increased in the media supplemented with doxycycline, however, the expression of Runx2 and noggin genes was upregulated only after 21 days of incubation in the osteogenic medium with doxycycline. Moreover, while the examination of ALP activity showed reduced activity in the control medium containing doxycycline, the accumulation of minerals remained unchanged in the cultures. We have found that the induced BMP-7 expression failed to induce osteogenic differentiation of DPSCs. We propose three different mechanisms that may worth investigating for the engineering of expression systems that can be used for the induction of differentiation of mesenchymal stem cells.

Cerium oxide nanoparticles loaded nanofibrous membranes promote bone regeneration for periodontal tissue engineering

Bone regeneration is a crucial part in the treatment of periodontal tissue regeneration, in which new attempts come out along with the development of nanomaterials. Herein, the effect of cerium oxide nanoparticles (CeO2 NPs) on the cell behavior and function of human periodontal ligament stem cells (hPDLSCs) was investigated. Results of CCK-8 and cell cycle tests demonstrated that CeO2 NPs not only had good biocompatibility, but also promoted cell proliferation. Furthermore, the levels of alkaline phosphatase activity, mineralized nodule formation and expressions of osteogenic genes and proteins demonstrated CeO2 NPs could promote osteogenesis differentiation of hPDLSCs. Then we chose electrospinning to fabricate fibrous membranes containing CeO2 NPs. We showed that the composite membranes improved mechanical properties as well as realized release of CeO2 NPs. We then applied the composite membranes to in vivo study in rat cranial defect models. Micro-CT and histopathological evaluations revealed that nanofibrous membranes with CeO2 NPs further accelerated new bone formation. Those exciting results demonstrated that CeO2 NPs and porous membrane contributed to osteogenic ability, and CeO2 NPs contained electrospun membrane may be a promising candidate material for periodontal bone regeneration.

Modification and characterization of an innovative polyvinyl alcohol-45S5 bioactive glass nanocomposite scaffold containing Donepezil hydrochloride for bone tissue engineering applications

The bone tissue engineering field is in desperate need of a suitable scaffold. We synthesized a polyvinyl alcohol (PVA) based scaffold and modified it by adding bioglass (BG) and Donepezil hydrochloride (DPH) to offset the lack of bioactivity and promote bone induction. XRD and FTIR analysis corroborated the successful chemical bonding of the compounds within the scaffold. Incorporating DPH leads to accelerated degradation and enhanced swelling of the composite. MTT and Acridine orange manifested increased adherence, viability, growth and proliferation of PVA/BG/DPH. Further, following osteogenic induction, PVA/BG/DPH directed hMSCs to synergistically boost the level of calcium biomineralization and alkaline phosphatase (ALP) activity.

The Validity of Serum Alkaline Phosphatase to Identify Nutritional Rickets in Nigerian Children on a Calcium-Deprived Diet.

Nutritional rickets results from the interaction of low vitamin D status and limited calcium intake. Serum alkaline phosphatase (AP) activity is a biomarker of impaired mineralization in rickets. To assess the performance of serum AP activity in identifying nutritional rickets in calcium-deprived Nigerian children. We reanalyzed data from a case-control study of children with active rickets and matched control subjects without rickets, using a multivariate logistic regression to assess the odds of rickets associated with AP activity, adjusting for age, sex, and weight-for-age z-score. A total of 122 children with rickets and 119 controls were included. Rachitic children had a mean (±SD) age of 54 ± 29 months, and 55 (45.1%) were male. Cases and controls had low dietary calcium intakes (216 ± 87 and 214 ± 96 mg/day, respectively). Serum AP activity levels in cases and controls were 812 ± 415 and 245 ± 78 U/L, respectively (P < 0.001). AP was negatively associated with 25-hydroxyvitamin D values (r = -0.34; P < 0.001). In the adjusted model, the odds ratio (95% CI) receiver operating characteristic curve was 0.978. AP > 350 U/L identified nutritional rickets in Nigerian children with sensitivity 0.93, specificity 0.92, positive likelihood ratio 11.3, and negative likelihood ratio 0.07. An AP > 350 U/L effectively discriminated between Nigerian children with and without nutritional rickets. AP is a low-cost biochemical test that could be used to screen for nutritional rickets, but cutoff values require validation in other populations, and laboratory values need to be standardized for widespread population studies.

Rifampicin induces the bone form of alkaline phosphatase in humans.

Pregnane X receptor (PXR) is a xenobiotic-sensing nuclear receptor that regulates drug metabolism in the liver and intestine. In our clinical trials on healthy volunteers to discover novel metabolic functions of PXR activation, we observed that rifampicin, a well-established ligand for human PXR, 600mg daily for a week, increased the plasma alkaline phosphatase (ALP) significantly compared with the placebo. Further analysis with lectin affinity electrophoresis revealed that especially the bone form of ALP was elevated. To investigate the mechanism(s) of bone ALP induction, we employed osteoblast lineage differentiated from human primary bone marrow-derived mesenchymal stromal cells. Rifampicin treatment increased ALP activity and mRNA level of bone biomarker genes (ALP, MGP, OPN and OPG). PXR expression was detected in the cells, but the expression was very low compared with the human liver. To further investigate the potential role of PXR in the ALP induction, we treated mice and rats with a rodent PXR ligand pregnenolone 16α-carbonitrile (PCN). However, PCN treatment did not increase plasma ALP activity or bone ALP mRNA expression. In conclusion, rifampicin treatment induces the bone form of ALP in the serum of healthy human volunteers. Further studies are required to establish the mechanism of this novel finding.

Carnosol induces the osteogenic differentiation of bone marrow-derived mesenchymal stem cells via activating BMP-signaling pathway.

Carnosol is a phenolic diterpene phytochemical found in rosemary and sage with reported anti-microbial, anti-oxidant, anti-inflammatory, and anti-carcinogenic activities. This study aimed to investigate the effect of carnosol on the lineage commitment of mouse bone marrow-derived mesenchymal stem cells (mBMSCs) into osteoblasts and adipocytes. Interestingly, carnosol stimulated the early commitment of mBMSCs into osteoblasts in dose-dependent manner as demonstrated by increased levels of alkaline phosphatase activity and Alizarin red staining for matrix mineralization. On the other hand, carnosol significantly suppressed adipogenesis of mBMSCs and downregulated both early and late markers of adipogenesis. Carnosol showed to induce osteogenesis in a mechanism mediated by activating BMP signaling pathway and subsequently upregulating the expression of BMPs downstream osteogenic target genes. In this context, treatment of mBMSCs with LDN-193189, BMPR1 selective inhibitor showed to abolish the stimulatory effect of carnosol on BMP2-induced osteogenesis. In conclusion, our data identified carnosol as a novel osteoanabolic phytochemical that can promote the differentiation of mBMSCs into osteoblasts versus adipocytes by activating BMP-signaling.

Culture strategy as a modulator of target assessments: Functionality of suspension versus hanging drop-derived choriocarcinoma spheroids as in vitro model of embryo implantation.

The choriocarcinoma spheroid model has been amply applied to study the underlying molecular mechanism of implantation. Reproducibility and functionality of spheroid tumor models were addressed precisely. To mimic embryo-endometrium crosstalk, no functional characteristics of spheroids have been provided based on culture strategies. In this study, choriocarcinoma spheroids were provided as suspension culture (SC) or hanging drop culture (HDC). Primary assessments were performed based on morphology, cellular density, and hormonal secretion. Spheroid-endometrial cross talk was assessed as coculture procedures. Further, alkaline phosphatase (ALP) activity and expression of genes involved in attachment, invasion, and inducing migration were quantified. We found HDC spheroids provided a homogenous-shaped aggregate with a high grade of viability, cellular integration, hormonal secretion, and the dominant role of WNTs expression in their microarchitecture. SC spheroids showed a higher level of ALP activity and the expression of integrated genes in modulating attachment, invasion, and migration abilities. Spheroid confrontation assays clearly clarified the superiority of SC spheroids to crosstalk with epithelial and stromal cells of endometrium in addition to motivating an ideal endometrial response. Conclusively, culture strategies by affecting various molecular signaling pathways should be chosen precisely according to specific target assessments. Specifically, SC assumed as an ideal model in spheroid-endometrial cross talk.

Coupling high frequency monitoring and bioassay experiments to investigate a harmful algal bloom in the Bay of Seine (French-English Channel)

Coastal ecosystems are increasingly threatened by eutrophication and dystrophy. In this context, the full pattern of a bloom dominated by the dinoflagellate, Lepidodinium chlorophorum, was investigated by a high frequency monitoring buoy equipped with sensors allowing nutrients and photosynthesis measurements. An increase of the N/P ratio affected phytoplankton physiology leading to bloom collapse with a slight oxygen depletion. In parallel, enrichment experiments were performed on the natural bloom population. After 5 days of incubation the community structure, using flow cytometry and several physiological parameters were analysed. The data reveal a potential N and P co-limitation and a decoupling between primary production and productivity in fully enriched conditions. Under unbalanced N/P inputs, high level of alkaline phosphatase activity and transparent exopolymeric particle production, which favour phytoplankton sedimentation, were observed. Nutrient inputs and their stoichiometry control phytoplankton growth, the community structure, physiological regulations, the fate of the bloom and consequences.

3D magnetic nanocomposite scaffolds enhanced the osteogenic capacities of rat bone mesenchymal stem cells in vitro and in a rat calvarial bone defect model by promoting cell adhesion.

Magnetic scaffolds incorporated with iron oxide nanoparticles (IONPs) are biocompatible and present excellent osteogenic properties. However, the underlying mechanism is unclear. In this study, 3D-printed poly(lactic-co-glycolic acid) scaffolds were coated with IONPs using layer-by-layer assembly (Fe-scaffold) to prepare magnetic scaffolds. The effects of this modification on osteogenesis were investigated by comparison with untreated scaffolds (Uncoated-scaffold). The results showed that the proliferation of rat bone mesenchymal stem cells (rBMSCs) on the Fe-scaffold was enhanced compared with those on the Uncoated-scaffold (p < 0.05). The alkaline phosphatase activity and expression levels of osteogenic-related genes of cells on the Fe-scaffold were higher than those on the Uncoated-scaffold (p < 0.05). Fe-scaffold was found to promote the cell adhesion compared with Uncoated-scaffold, including increasing the adhered cell number, promoting cell spreading and upregulating the expression levels of adhesion-related genes integrin α1 and β1 and their downstream signaling molecules FAK and ERK1/2 (p < 0.05). Moreover, the amount of new bone formed in rat calvarial defects at 8 weeks decreased in the order: Fe-scaffold > Uncoated-scaffold > Blank-control (samples whose defects were left empty) (p < 0.05). Therefore, 3D magnetic nanocomposite scaffolds enhanced the osteogenic capacities of rBMSCs in vitro and in a rat calvarial bone defect model by promoting cell adhesion. The mechanisms were attributed to the alteration in its hydrophilicity, surface roughness, and chemical composition.

Near-infrared 940-nm diode laser photobiomodulation of inflamed periodontal ligament stem cells.

Photobiomodulation (PBM) is an acceptable method of stimulating stem cells through its non-invasive absorption by the cell photoreceptors and the induction of cellular response. The current research was aimed at evaluating the effect of near-infrared PBM on proliferation and osteogenic differentiation in inflamed periodontal ligament stem cells (I-PDLSCs). I-PDLSCs were isolated and characterized. Third passage cells were irradiated with 940-nm laser at an output power of 100 mW in a continuous wave. A fluence of 4 J/cm2 in three sessions at 48-h intervals was applied and compared with non-irradiated controls. Cell viability and proliferation were evaluated by MTT assay. Alkaline phosphatase activity, quantitative Alizarin red staining test, and q-RT-PCR were used to evaluate the osteogenic properties of the I-PDLSCs in four groups of (a) osteogenic differentiation medium + laser (ODM + L), (b) osteogenic differentiation medium without laser (ODM), (c) non-osteogenic differentiation medium + laser (L), and (d) non-osteogenic differentiation medium (control). There was a non-significant increase in the viability of cells at 48- and 72-h post last laser irradiation. Alizarin red staining revealed no significant stimulatory effect of PBM at 14 and 21 days. However, alkaline phosphatase activity was significantly higher in the L + ODM group. Expression of osteogenic-related genes had a statistically significant increase at 21-day post irradiation. The irradiation used in the present study showed no significant increase in the proliferation of I-PDLSCs by PBM. However, expression levels of osteogenic-related genes and alkaline phosphatase activity were significantly increased in irradiated groups.

Hematological parameters and protein metabolism in the blood of pregnant rats under the effect of vanadium citrate

Dose-dependent changes in protein metabolism in the blood and hematological parameters of pregnant rats under the effect of vanadium citrate are presented in the article. The animals were divided into five groups: group I – non-pregnant females, II – pregnant females consuming pure water without additives, III, IV, V – females which during the mating and pregnancy period received the solution of vanadium citrate at concentrations of 0.03, 0.125 and 0.50 μg V/mL water. The research findings show that in pregnant animals of group II, the level of urea and alkaline phosphatase activity increased, meanwhile aspartate aminotransferase activity decreased, as compared to the non-pregnant females of group І. The levels of total protein and albumin decreased; however, the content of β-globulins increased in the pregnant animals of group II, as compared with that in group I. Also, in the rats of group II, there was a decrease in hemolysis time, total content of erythrocytes and hemoglobin, the content of old and mature erythrocytes, while the content of young erythrocytes increased, as compared to group I. The platelet content and thrombocrit in rats of group II increased in comparison with group I. The content of leukocytes and lymphocytes in pregnant animals of group II decreased, while the content of granulocytes increased, in contrast to non-pregnant rats. Under the effect of vanadium citrate at concentrations of 0.03–0.50 μg V/mL, there was a significant increase in the maximum number of prohemolized erythrocytes, the time of maximum hemolysis was delayed by 0.4–0.6 min, as compared with the pregnant rats of group II. This did not affect the time of total hemolysis in rats of groups III and V, as compared with the pregnant animals in group II. Under the effect of vanadium citrate, an increase in the content of young erythrocytes was observed, as compared with group II. The hemoglobin content decreased at the concentration of 0.125 μg V/mL, while at the concentration of 0.50 μg V/mL it increased, as compared to the pregnant animals of group II. Also, under the effect of vanadium citrate there was a decrease in the mean hemoglobin concentration in the erythrocyte. In pregnant animals fed with vanadium citrate solutions, the platelet content and thrombocrit, the relative width of platelet distribution by volume decreased, as compared with the pregnant rats of group II. The content of leukocytes, lymphocytes and granulocytes under the effect of vanadium citrate increased, as compared with the pregnant animals in group II. Under the effect of vanadium citrate at the concentration of 0.03 μg V/mL, the level of albumin, creatinine and aspartate aminotransferase activity increased in blood plasma in comparison with group II. Meanwhile, at the concentration of 0.125 μg V/mL, the relative content of γ-globulins and aspartate aminotransferase activity increased, alkaline phosphatase activity and urea level decreased in comparison with group II. However at the concentration of 0.50 μg V/mL, the relative α- and γ-globulins content and aspartate aminotransferase activity increased, at the same time, the relative β-globulins content and urea level decreased in comparison with group II. Therefore, vanadium citrate normalizes the indicators of protein metabolism during pregnancy, thus it can be considered as a potential dietary drug for the pregnant.

Surface Topography of Titanium Affects Their Osteogenic Potential through DNA Methylation.

It is widely accepted that sandblasted/large-grit/acid-etched (SLA) surfaces of titanium (Ti) have a higher osteogenic potential than machined ones. However, most studies focused on differential gene expression without elucidating the underlying mechanism for this difference. The aim of this study was to evaluate how the surface roughness of dental Ti implants affects their osteogenic potential. Mouse preosteoblast MC3T3-E1 cells were seeded on machined and SLA Ti discs. The cellular activities of the discs were analyzed using confocal laser scanning microscopy, proliferation assays, and real-time polymerase chain reaction (PCR). DNA methylation was evaluated using a methylation-specific PCR. The cell morphology was slightly different between the two types of surfaces. While cellular proliferation was slightly greater on the machined surfaces, the osteogenic response of the SLA surfaces was superior, and they showed increased alkaline phosphatase (Alp) activity and higher bone marker gene expression levels (Type I collagen, Alp, and osteocalcin). The degree of DNA methylation on the Alp gene was lower on the SLA surfaces than on the machined surfaces. DNA methyltransferase inhibitor stimulated the Alp gene expression on the machined surfaces, similar to the SLA surfaces. The superior osteogenic potential of the SLA surfaces can be attributed to a different epigenetic landscape, specifically, the DNA methylation of Alp genes. This finding offers novel insights into epigenetics to supplement genetics and raises the possibility of using epidrugs as potential therapeutic targets to enhance osteogenesis on implant surfaces.

Insulin-like growth factor 2-enhanced osteogenic differentiation of stem cell spheroids by regulation of Runx2 and Col1 expression.

Insulin-like growth factor 2 (IGF-2) is a growth factor that is involved in various functions of cells, including stem cells. The effects of IGF-2 on the cellular viability and osteogenic differentiation of stem cell spheroids were investigated in the present study. Stem cell spheroids were formed using concave microwells in the presence of IGF-2 at final concentrations of 0, 10 and 100 ng/ml. Cellular viability was measured qualitatively using a microscope and quantitatively using an assay kit based on water-soluble tetrazolium salt. The level of alkaline phosphatase activity, and an anthraquinone dye assay for calcium deposit evaluation, were used to assess osteogenic differentiation. A quantitative PCR analysis was conducted to evaluate the expression of Runx2 and Col1. Spheroid formation was noticed on day 1 in the microwells, and the spheroidal shape was maintained up to day 7. The cell viability assay values for IGF-2 at 0, 10 and 100 ng/ml at day 1 were 0.193±0.002, 0.191±0.002 and 0.201±0.006, respectively (P>0.05). The absorbance values at 405 nm for the alkaline phosphatase activity assays on day 21 were 0.221±0.006, 0.375±0.010 and 0.280±0.015 for IGF-2 at 0, 10 and 100 ng/ml, respectively. There were significantly higher values for IGF-2 in the 10 and 100 ng/ml groups when compared with the control (P<0.05). Significantly higher Alizarin red staining was noted for IGF-2 in the 10 ng/ml group when compared with the unloaded control at day 21 (P<0.05). Quantitative PCR revealed that mRNA levels of Runx2 and Col1 were significantly higher at 100 ng/ml on day 7. Conclusively, the present study demonstrated that the application of IGF-2 increased alkaline phosphatase activity, Alizarin red staining, and Runx2 and Col1 expression of stem cell spheroids.

Polycaprolactone-Based Scaffolds Facilitates Osteogenic Differentiation of Human Adipose-Derived Stem Cells in a Co-Culture System.

(1) Background: Stem cells in combination with scaffolds and bioactive molecules have made significant contributions to the regeneration of damaged bone tissues. A co-culture system can be effective in enhancing the proliferation rate and osteogenic differentiation of the stem cells. Hence, the aim of this study was to investigate the osteogenic differentiation of human adipose derived stem cells when co-cultured with human osteoblasts and seeded on polycaprolactone (PCL):hydroxyapatite (HA) scaffold; (2) Methods: Human adipose-derived stem cells (ASC) and human osteoblasts (HOB) were seeded in three different ratios of 1:2, 1:2 and 2:1 in the PCL-HA scaffolds. The osteogenic differentiation ability was evaluated based on cell morphology, proliferation rate, alkaline phosphatase (ALP) activity, calcium deposition and osteogenic genes expression levels using quantitative RT-PCR; (3) Results: The co-cultured of ASC/HOB in ratio 2:1 seeded on the PCL-HA scaffolds showed the most positive osteogenic differentiation as compared to other groups, which resulted in higher ALP activity, calcium deposition and osteogenic genes expression, particularly Runx, ALP and BSP. These genes indicate that the co-cultured ASC/HOB seeded on PCL-HA was at the early stage of osteogenic development; (4) Conclusions: The combination of co-culture system (ASC/HOB) and PCL-HA scaffolds promote osteogenic differentiation and early bone formation.

Hypophosphatasia screening in pediatric age based on records

Introduction: hypophosphatasia (HPP) is a congenital disease, characterized by a defect in bone and dentary mineralization, secondary to a deficiency in the biosynthesis of non-specific tissue isoenzyme of alkaline phosphatase (TNSALP), resulting in decreased levels of alkaline phosphatase (ALP) activity and the extracellular accumulation of its substrates. Our goal was to establish the interest of screening the hospital databases of pediatric patients with low levels of ALP for the diagnosis of HPP. Materials and methods: during the period from September 2016 to September 2017, 23231 patients were tested for ALP, 1752 of them showed low levels of ALP. Based on the clinic, basal disease and that in previous analyses they did not present ALT norm values, 14 cases were selected: 8 cases associated with early puberty, 1 case of low size, 1 case of liver disease and myasthenia and 1 case of teething problems. ALPL gene was studied in those cases. Results: the latter case was of an 8-year-old male with a pathological variant of HPP: c.343_348dupACCGCC (p.Thr115_Ala116dup) in exon 5 in dominant heterozygous, inherited from his mother. At the substrate level the levels of pyridoxal-5-phosphate were above 50μg/L. Conclusion: the diagnostic strategy with a high index of clinical suspicion of HPP should include the observation of low levels of serum ALP activity. Our study shows that HPP is an underdiagnosed disease.An appropriate protocol to detect HPP in a clinical setting in tertiary care hospitals is required.

Histatin‐1 is a novel osteogenic factor that promotes bone cell adhesion, migration, and differentiation

Histatin-1 is a salivary antimicrobial peptide involved in the maintenance of enamel and oral mucosal homeostasis. Moreover, Histatin-1 has been shown to promote re-epithelialization in soft tissues, by stimulating cell adhesion and migration in oral and dermal keratinocytes, gingival and skin fibroblasts, endothelial cells and corneal epithelial cells. The broad-spectrum activity of Histatin-1 suggests that it behaves as a universal wound healing promoter, although this is far from being clear yet. Here, we report that Histatin-1 is a novel osteogenic factor that promotes bone cell adhesion, migration and differentiation. Specifically, Histatin-1 promoted cell adhesion, spreading and migration of SAOS-2 cells and MC3T3-E1 pre-osteoblasts in vitro, when placed on a fibronectin matrix. Besides, Histatin-1 induced the expression of osteogenic genes, including osteocalcin, osteopontin and Runx2, and increased both activity and protein levels of alkaline phosphatase. Furthermore, Histatin-1 promoted mineralization in vitro, as it augmented the formation of calcium deposits in both SAOS-2 and MC3T3-E1 cells. Mechanistically, although Histatin-1 failed to activate ERK1/2, FAK and Akt, which are signaling proteins associated with osteogenic differentiation or cell migration, it triggered nuclear re-localization of β-catenin. Strikingly, the effects of Histatin-1 were recapitulated in cells that are non-osteogenically committed, since it promoted surface adhesion, migration and the acquisition of osteogenic markers in primary mesenchymal cells derived from the apical papilla and dental pulp. Collectively, these observations indicate that Histatin-1 is a novel osteogenic factor that promotes bone cell differentiation, surface adhesion and migration, as crucial events required for bone tissue regeneration. This article is protected by copyright. All rights reserved.

The effects of fipronil exposure on oxidative stress, non-specific immunity, autophagy, and apoptosis in the common carp.

The increase in the area treated with the insecticide fipronil has caused concern for aquatic organisms such as fish. Here, we assessed the effect of fipronil on carp indexes of non-specific immunity, oxidative stress, autophagy, and apoptosis following exposure to 0.074 mg/L and 0.185 mg/L of fipronil in the aqueous environment for 1 day, 3 days, 5 days, and 7 days. It was found that glutathione (GSH), malonaldehyde (MDA), and superoxide dismutase (SOD) in gills were significantly reduced (P < 0.05). The increase in exposure time increases the impact on GSH, SOD, and MDA parameters in the liver and intestine. Liver acid phosphatase (ACP), alkaline phosphatase (AKP), and lysozyme (LZM) activity levels increased significantly in the treatment group on the first day after exposure, except for the 0.074 mg/L group of ACP (P < 0.05). The mRNA expression levels of autophagy-related genes ATG12, ATG5, ATG16L, LC3-II, and BECN1 were generally elevated in the liver and intestine during the initial exposure period (P < 0.05), while mTOR was significantly reduced on the first and third days after treatment (P < 0.05). From the results of Western blotting (WB), we can see that the amount of LC3-II was significantly higher than that of LC3-I at 1, 3, and 5 days of exposure (P < 0.05). Furthermore, the apoptosis-related gene Bcl-2 reached its peak in the liver, intestine, and gill on the first day, and caspase3 was significantly downregulated throughout the exposure period (P < 0.05). The results showed that fipronil was potentially harmful to carp and should be used moderately to reduce the damage to aquatic ecosystems. This study complements the mechanism theory of fipronil on fish toxicology and has a certain value for human health risk assessment.

Incorporation of Calcium Sulfate Dihydrate into a Mesoporous Calcium Silicate/Poly-ε-Caprolactone Scaffold to Regulate the Release of Bone Morphogenetic Protein-2 and Accelerate Bone Regeneration.

Tissue engineering and scaffolds play an important role in tissue regeneration by supporting cell adhesion, proliferation, and differentiation. The design of a scaffold is critical in determining its feasibility, and it is critical to note that each tissue is unique in terms of its morphology and composition. However, calcium-silicate-based scaffolds are undegradable, which severely limits their application in bone regeneration. In this study, we developed a biodegradable mesoporous calcium silicate (MS)/calcium sulfate (CS)/poly-ε-caprolactone (PCL) composite and fabricated a composite scaffold with 3D printing technologies. In addition, we were able to load bone morphogenetic protein-2 (BMP-2) into MS powder via a one-step immersion procedure. The results demonstrated that the MS/CS scaffold gradually degraded within 3 months. More importantly, the scaffold exhibited a gradual release of BMP-2 throughout the test period. The adhesion and proliferation of human dental pulp stem cells on the MS/CS/BMP-2 (MS/CS/B) scaffold were significantly greater than that on the MS/CS scaffold. It was also found that cells cultured on the MS/CS/B scaffold had significantly higher levels of alkaline phosphatase activity and angiogenic-related protein expression. The MS/CS/B scaffold promoted the growth of new blood vessels and bone regeneration within 4 weeks of implantation in rabbits with induced critical-sized femoral defects. Therefore, it is hypothesized that the 3D-printed MS/CS/B scaffold can act both as a conventional BMP-2 delivery system and as an ideal osteoinductive biomaterial for bone regeneration.

Comparing the osteogenic potential of schneiderian membrane and dental pulp mesenchymal stem cells: an in vitro study.

Mesenchymal stem cells, being characterized by high self-renewal capacity and multi-lineage differentiation potential, are widely used in regenerative medicine especially for repair of bone defects in patients with poor bone regenerative capacity. In this study, we aimed to compare the osteogenic potential of human maxillary schneiderian sinus membrane (hMSSM)-derived stem cells versus permanent teeth dental pulp stem cells (DPSCs). Both cells types were cultivated in osteogenic and non-osteogenic inductive media. Alkaline phosphatase (ALP) activity assay and quantitative real-time PCR analysis were carried out to assess osteogenic differentiation. We showed that ALP activity and osteoblastic markers transcription levels were more striking in hMSSM-derived stem cells than DPSCs. Our results highlight hMSSM-derived stem cells as a recommended stem cell type for usage during bone tissue regenerative therapy.