Osteopontin: Relation between Adipose Tissue and Bone Homeostasis

Identification of potential diagnostic biomarkers for tenosynovial giant cell tumour by integrating microarray and single-cell RNA sequencing data

PURPOSE

Tenosynovial giant cell tumour (TGCT) is a benign hyperplastic and inflammatory disease of the joint synovium or tendon sheaths, which may be misdiagnosed due to its atypical symptoms and imaging features. We aimed to identify biomarkers with high sensitivity and specificity to aid in diagnosing TGCT.

METHODS

Two scRNA-seq datasets (GSE210750 and GSE152805) and two microarray datasets (GSE3698 and GSE175626) were downloaded from the Gene Expression Omnibus (GEO) database. By integrating the scRNA-seq datasets, we discovered that the osteoclasts are abundant in TGCT in contrast to the control. The single-sample gene set enrichment analysis (ssGSEA) further validated this discovery. Differentially expressed genes (DEGs) of the GSE3698 dataset were screened and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of DEGs were conducted. Osteoclast-specific up-regulated genes (OCSURGs) were identified by intersecting the osteoclast marker genes in the scRNA-seq and the up-regulated DEGs in the microarray and by the least absolute shrinkage and selection operator (LASSO) regression algorithm. The expression levels of OCSURGs were validated by an external dataset GSE175626. Then, single gene GSEA, protein-protein interaction (PPI) network, and gene-drug network of OCSURGs were performed.

RESULT

22 seurat clusters were acquired and annotated into 10 cell types based on the scRNA-seq data. TGCT had a larger population of osteoclasts compared to the control. A total of 159 osteoclast marker genes and 104 DEGs (including 61 up-regulated genes and 43 down-regulated genes) were screened from the scRNA-seq analysis and the microarray analysis. Three OCSURGs (MMP9, SPP1, and TYROBP) were finally identified. The AUC of the ROC curve in the training and testing datasets suggested a favourable diagnostic capability. The PPI network results illustrated the protein-protein interaction of each OCSURG. Drugs that potentially target the OCSURGs were predicted by the DGIdb database.

CONCLUSION

MMP9, SPP1, and TYROBP were identified as osteoclast-specific up-regulated genes of the tenosynovial giant cell tumour via bioinformatic analysis, which had a reasonable diagnostic efficiency and served as potential drug targets.

DNA methylation pattern and mRNA expression of OPN promoter in sika deer antler tip tissues

In order to explore the biological role of OPN gene during the growth of sika deer antler, the dermis, mesenchyme, precartilage and cartilage tissues of sika deer antler tip at the early period of the antler with a saddle-like appearance (30 days), the rapid growth period of the antler with two branches (60 days), and the final period of the antler with three branches (90 days) were analyzed. Bisulfite sequencing PCR (BSP) and quantitative real-time PCR (qRT-PCR) were used to explore the DNA promoter methylation and mRNA expression of OPN in sika deer antler from the perspective of space and time. The test results showed that: 1) The methylation rates of OPN promoter at the early, middle and late periods of dermis tissue were (40.48±0.82)%, (40.00±1.43)%, and (39.05±0.82)%; The methylation rates in mesenchyme tissue were (37.62±0.82)%, (34.76±2.18)%, and (38.57±1.43)%; The methylation rates in precartilage tissue were (36.67±0.28)%, (29.52±1.65)%, (28.10±2.18)%; The methylation rates in cartilage tissue were (31.90±1.65)%, (26.67±1.65)%, (24.29±1.43)%. 2) There are 7 CpG sites in the OPN promoter region, and the 3 CpG sites of -367 bp, -245 bp and -31 bp are all methylated to different level. 3) The methylation level of OPN in the dermis, mesenchyme, precartilage and cartilage tissues decreased in sequence at the same growth period. At the middle and late periods, the methylation level of the promoter region of the precartilage tissue was significantly different from that of the dermis and mesenchyme tissues (P<0.05); At different growth periods, the methylation level of the promoter region of cartilage tissue was extremely significantly different from that of dermis and mesenchyme tissues (P<0.01); In the same tissue, the methylation level of the promoter region at the middle period was down-regulated compared with the early period, and the methylation level of the promoter region at the early period and the middle period was extremely significantly different in the precartilage and cartilage (P<0.01). 4) OPN mRNA is highly expressed in precartilage and cartilage tissues. 5) The methylation level of OPN promoter was negatively correlated with mRNA expression level. In summary, it is speculated that the OPN gene, which may be regulated by the DNA methylation level of the promoter, promotes the growth and development of deer antler mainly by regulating the growth of precartilage and cartilage tissues.

Apolipoprotein D modulates lipid mediators and osteopontin in an anti-inflammatory direction

BACKGROUND

HDL has been proposed to possess anti-inflammatory properties; however, the detail mechanisms have not been fully elucidated.

METHODS

We investigated the roles of Apolipoprotein D (ApoD) in the pathogenesis of inflammation in the mouse model of diet-induced obesity and that of lipopolysaccharide-induced sepsis and the in vitro experiments. Furthermore, we analyzed serum ApoD levels in human subjects.

RESULTS

The overexpression of human ApoD decreased the plasma IL-6 and TNF-a levels in both mice models. Lipidomics analyses demonstrated association of ApoD with increase of arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid, as well as of their metabolites, and of the anti-inflammatory molecule sphingosine 1-phosphate, and decrease of proinflammatory lysophosphatidic acids and lysophosphatidylinositol. ApoD-containing lipoproteins might directly bind eicosapentaenoic acid and docosahexaenoic acid. The modulations of the lysophosphatidic acid and sphingosine 1-phosphate levels resulted from the suppression of autotaxin expression and elevation of apolipoprotein M (ApoM), respectively. Moreover, ApoD negatively regulated osteopontin, a proinflammatory adipokine. The activation of PPARg by ApoD might suppress autotaxin and osteopontin. Serum ApoD levels were negatively correlated with the serum osteopontin and autotaxin levels and, positively with serum ApoM levels.

CONCLUSION

ApoD is an anti-inflammatory apolipoprotein, which modulates lipid mediators and osteopontin in an anti-inflammatory direction.

The Neglected Factor in the Relationship between Executive Functioning and Obesity: The Role of Motor Control

Background: The association between obesity and executive functions (EFs) is highly controversial. It has been suggested that waist circumference (WC), compared to body mass index (BMI), is a better indicator of fat mass and EFs in obesity. Moreover, according to the viewpoint that the brain’s functional architecture meets the need for interactive behavior, we hypothesize that the relationship between EFs and body weight might be mediated by the motor performance. Methods: General executive functioning (frontal assessment battery-15), additional cognitive subdomains (trail making test and digit span backward), and motor performance (finger tapping task) were assessed in a sample that included 330 volunteers (192 females, M age = 45.98 years, SD = 17.70, range = 18–86 years). Results: Hierarchical multiple regression analysis indicated that the FAB15 score and FTT negatively predicted WC but not BMI. A subsequent mediation analysis highlighted that the indirect effect of FAB15 on WC through finger tapping was statistically significant. Conclusions: Our results suggest that WC, as compared to BMI, is a more effective measure for studying the association between EFs and body weight. Still, we found that the motor domain partially mediates the dynamics of such a relationship.

Factorial Model of Obese Adolescents: The Role of Body Image Concerns and Selective Depersonalization-A Pilot Study

BACKGROUND

The relationship binding body weight to psychological well-being is unclear. The present study aims at identifying the contribution, and specificity, of some dimensions (i.e., eating-related symptoms, body image disorders, eating habits, personality traits, and emotional difficulties) characterizing the psychological profile of obese adolescents (749 participants, 325 females; 58.3% normal-weight, 29.9% overweight, and 11.7% obese; mean age = 16.05, SD = 0.82).

METHODS

By introducing the scores obtained by standardized self-report tools into a generalized linear model, a factorial reduction design was used to detect the best fitting discriminant functions and the principal components explaining the higher proportion of the variance.

RESULTS

We found two discriminant functions correctly classifying 87.1% of normal-weight, 57.2% of overweight, and 68.2% of obese adolescents. Furthermore, two independent factors, explaining 69.68% of the total variance, emerged.

CONCLUSIONS

The first factor, "Body Image Concerns", included the drive for thinness, body dissatisfaction, and interpersonal distrust. The second factor, "Selective Depersonalization", included a trend toward depersonalization and dissatisfaction with the torso. The neurophysiological implications of our findings will be discussed.

Carbon Monoxide-Releasing Molecule-3 Enhances Osteogenic Differentiation of Rat Bone Marrow Mesenchymal Stem Cells via miR-195-5p/Wnt3a Pathway

Purpose

Bone marrow-derived mesenchymal stem cells (BMSCs) are hopeful in promoting bone regeneration as their pluripotency in differentiation. Our previous study showed that carbon monoxide-releasing molecule-3 (CORM-3) increased the osteogenic differentiation of rat BMSCs in vitro. However, the mechanism remained unclear. MicroRNAs (miRNAs) play a very important role in modulating the osteogenic differentiation of BMSCs. Therefore, we researched the miRNAs involved in CORM-3-stimulated osteogenic differentiation.

Methods

The CORM-3-stimulated osteogenic differentiation of rat BMSCs was further studied in vivo. Based on the gene sequencing experiment, the rat BMSCs were transfected with miR-195-5p mimics and inhibitor, pcDNA3.1-Wnt3a and Wnt3a siRNA. The osteogenic differentiation of rat BMSCs was measured by quantitative real-time polymerase chain reaction, Western blot and alizarin red staining. Additionally, the targeting relationship between miR-195-5p and Wnt3a was confirmed by the dual-luciferase assay.

Results

MiR-195-5p was down-expressed during the CORM-3-stimulated osteogenic differentiation of rat BMSCs. CORM-3-stimulated osteogenic differentiation of rat BMSCs was inhibited with miR-195-5p overexpression, evidenced by significantly reduced mRNA and protein expressions of runt-related transcription factor 2 and osteopontin, and matrix mineralization demonstrated. On the contrary, the osteogenic differentiation was enhanced with inhibition of miR-195-5p. CORM-3-stimulated osteogenic differentiation of rat BMSCs was increased by overexpression of Wnt3a, while the opposite was observed in the Wnt3a-deficient cells. Moreover, the decreased osteogenic differentiation capacity by increased expression of miR-195-5p was rescued by Wnt3a overexpression, showing miR-195-5p directly targeted Wnt3a.

Conclusion

These results demonstrate that CORM-3 promoted osteogenic differentiation of rat BMSCs via miR-195-5p/Wnt3a, which bodes well for the application of CORM-3 in the treatment of periodontal disease and other bone-defect diseases.

Executive Functions in Overweight and Obese Treatment-Seeking Patients: Cross-Sectional Data and Longitudinal Perspectives

BACKGROUND

Recent evidence suggests that a higher body weight may be linked to cognitive impairment in different domains involving executive/frontal functioning. However, challenging results are also available. Accordingly, our study was designed to verify whether (i) poor executive functions are related to a higher body weight and (ii) executive functioning could contribute to weight loss in treatment-seeking overweight and obese patients.

METHODS

We examined general executive functioning, inhibitory control, verbal fluency, and psychomotor speed in a sample including 104 overweight and obese patients. Forty-eight normal-weight subjects participated in the study as controls.

RESULTS

Univariate Analysis of Variance showed that obese patients obtained lower scores than overweight and normal-weight subjects in all executive measures, except for errors in the Stroop test. However, when sociodemographic variables entered the model as covariates, no between-group difference was detected. Furthermore, an adjusted multiple linear regression model highlighted no relationship between weight loss and executive scores at baseline.

CONCLUSIONS

Our results provide further evidence for the lack of association between obesity and the executive domains investigated. Conflicting findings from previous literature may likely be due to the unchecked confounding effects exerted by sociodemographic variables and inclusion/exclusion criteria.

The Beneficial Effects of Physical Activity in Lung Cancer Prevention and/or Treatment

Lung cancer is the most lethal cancer: it has a significant incidence and low survival rates. Lifestyle has an important influence on cancer onset and its progression, indeed environmental factors and smoke are involved in cancer establishment, and in lung cancer. Physical activity is a determinant in inhibiting or slowing lung cancer. Certainly, the inflammation is a major factor responsible for lung cancer establishment. In this scenario, regular physical activity can induce anti-inflammatory effects, reducing ROS production and stimulating immune cell system activity. On lung function, physical activity improves lung muscle strength, FEV1 and forced vital capacity. In lung cancer patients, it reduces dyspnea, fatigue and pain. Data in the literature has shown the effects of physical activity both in in vivo and in vitro studies, reporting that its anti-inflammatory action is determinant in the onset of human diseases such as lung cancer. It has a beneficial effect not only in the prevention of lung cancer, but also on treatment and prognosis. For these reasons, it is retained as an adjuvant in lung cancer treatment both for the administration and prognosis of this type of cancer. The purpose of this review is to analyze the role of physical activity in lung cancer and to recommend regular physical activity and lifestyle changes to prevent or treat this pathology.

A new ex vivo model of the bone tissue response to the hyperglycemic environment - The embryonic chicken femur organotypic culture in high glucose conditions

Diabetes mellitus (DM) embrace a group of chronic metabolic conditions with a high morbidity, causing deleterious effects in different tissues and organs, including bone. Hyperglycemia seems to be one of the most contributing etiological factors of bone-related alterations, altering metabolic functionality and inducing morphological adaptations. Despite the established models for the assessment of bone functionality in hyperglycemic conditions, in vitro studies present a limited representativeness given the imperfect cell-cell and cell-matrix interactions, and restricted three-dimensional spatial arrangement; while in vivo studies raise ethical issues and offer limited mechanistic characterization, given the modulatory influence of many systemic factors and/or regulatory systems. Accordingly, the aim of this study is to establish and characterize an innovative ex vivo model of the bone tissue response to hyperglycemia, reaching hand of the organotypic culture of embryonic chicken femurs in high glucose conditions, showcasing the integrative responsiveness of the model regarding hyperglycemia-induced alterations. A thorough assessment of the cellular and tissue functionality was further conducted. Results show that, in high glucose conditions, femurs presented an increased cell proliferation and enhanced collagen production, despite the altered protein synthesis, substantiated by the increased carbonyl content. Gene expression analysis evidenced that high glucose levels induced the expression of pro-inflammatory and early osteogenic markers, further impairing the expression of late osteogenic markers. Furthermore, the tissue morphological organization and matrix mineralization were significantly altered by high glucose levels, as evidenced by histological, histochemical and microtomographic evaluations. Attained data is coherent with acknowledged hyperglycemia-induced bone tissue alterations, validating the models' effectiveness, and evidencing its integrative responsiveness regarding cell proliferation, gene and protein expression, and tissue morpho-functional organization. The assessed ex vivo model conjoins the capability to access both cellular and tissue outcomes in the absence of a systemic modulatory influence, outreaching the functionality of current experimental in vitro and in vivo models of the diabetic bone condition.

Li-Doped Ti Surface for the Improvement of Osteointegration

Aseptic loosening is the main factor that leads to the failure of orthopedic implants. Enhancing the early osteointegration of a bone implant can lower the risk of aseptic loosening. Here, a Li-doped surface was constructed on a Ti surface via plasma electrolytic oxidation (PEO) to improve osteointegration. The prepared Li-doped PEO coating showed a porous morphology and the sustained release of Li ions. In vitro results of rat bone marrow mesenchymal stem cell (rBMSC) culture studies suggested that the Li-doped Ti surface significantly favored cell adhesion. Moreover, it was found that the Li-doped surface enhanced alkaline phosphatase activity and extracellular matrix mineralization of rBMSCs. In addition, the surface improved the expression of osteogenesis-related genes. Furthermore, a bone implantation model indicated that the Li-doped Ti surface showed improved osteointegration. The incorporation of Li into a Ti surface is a promising method for orthopedic applications.

Evaluation of Bone Mineral Density, Serum Osteocalcin, and Osteopontin Levels in Postmenopausal Women with Type 2 Diabetes Mellitus, with/without Osteoporosis

OBJECTIVE

Osteoporosis (OP) is a worldwide ailment; we aim to establish new biomarkers in diagnosis by determining the levels of serum osteocalcin and osteopontin along with bone mineral density (BMD) and lumbar T-score, in postmenopausal women with type 2 diabetes mellitus (T2DM) with or without OP.

METHODS

This observational study included 160 postmenopausal women who were an attendee at outpatient clinics in Al-Hussein Hospital, Thi-Qar province; subdivided into 3 groups based on their T-score testing: Group I (n = 40) comprised postmenopausal women without T2DM as controls, Group II (n = 60) comprised postmenopausal women with T2DM but without OP, and Group III (n = 60) comprised postmenopausal women with T2DM with OP. The dual-energy X-ray absorptiometry was used to measure the BMD (total body, lumbar spine, and femoral) and T-score for lumbar spine and femoral. Glycosylated hemoglobin (HbA1c), fasting blood glucose (FBG), osteocalcin, and osteopontin levels were assessed in all three groups.

RESULTS

Compared with controls, Group III demonstrated significantly lower BMD (total body, lumbar spine, and femoral), T-score for lumbar spine and femoral, serum osteocalcin, and osteopontin levels than Group II and Group I (P < 0.001). FBG and HbA1c levels were significantly higher in Group III than in Groups I and II (P < 0.001). A negative correlation was proved between HbA1c levels with BMD, osteocalcin levels, and osteopontin levels in the three groups.

CONCLUSIONS

Iraqi postmenopausal women with T2DM had a significantly lower bone mineral density, serum osteocalcin, and osteopontin levels. These results may serve as adjuvants in screening for OP, particularly among diabetic patients.

Osteopontin, a bridge links osteoarthritis and osteoporosis

Osteoarthritis (OA) is the most prevalent joint disease characterized by degradation of articular cartilage, inflammation, and changes in periarticular and subchondral bone of joints. Osteoporosis (OP) is another systemic skeletal disease characterized by low bone mass and bone mineral density (BMD) accompanied by microarchitectural deterioration in bone tissue and increased bone fragility and fracture risk. Both OA and OP are mainly affected on the elderly people. Recent studies have shown that osteopontin (OPN) plays a vital role in bone metabolism and homeostasis. OPN involves these biological activities through participating in the proliferation, migration, differentiation, and adhesion of several bone-related cells, including chondrocytes, synoviocytes, osteoclasts, osteoblasts, and marrow mesenchymal stem cells (MSCs). OPN has been demonstrated to be closely related to the occurrence and development of many bone-related diseases, such as OA and OP. This review summarizes the role of OPN in regulating inflammation activity and bone metabolism in OA and OP. Furthermore, some drugs that targeted OPN to treat OA and OP are also summarized in the review. However, the complex mechanism of OPN in regulating OA and OP is not fully elucidated, which drives us to explore the depth effect of OPN on these two bone diseases.

Endocrine Regulation of Extra-skeletal Organs by Bone-derived Secreted Protein and the effect of Mechanical Stimulation

Bone serves as the support for body and provide attachment points for the muscles. The musculoskeletal system is the basis for the human body to complete exercise. Studies believe that bone is not only the basis for constructing structures, but also participates in the regulation of organs outside bone. The realization of this function is closely related to the protein secreted by bone. Whether bone can realize their positions in the human body is also related to their secretion. Bone-derived proteins provide a medium for the targeted regulation of bones on organs, making the role of bone in human body more profound and concrete. Mechanical stimulation effects the extra-skeletal organs by causing quantitative changes in bone-derived factors. When bone receives mechanical stimulation, the nichle of bone responds, and the secretion of various factors changes. However, whether the proteins secreted by bone can interfere with disease requires more research. In this review article, we will first introduce the important reasons and significance of the in-depth study on bone-derived secretory proteins, and summarize the locations, structures and functions of these proteins. These functions will not only focus on the bone metabolism process, but also be reflected in the cross-organ regulation. We specifically explain the role of typical bone-derived secretory factors such as osteocalcin (OCN), osteopontin (OPN), sclerostin (SOST) and fibroblast growth factor 23 (FGF23) in different organs and metabolic processes, then establishing the relationship between them and diseases. Finally, we will discuss whether exercise or mechanical stimulation can have a definite effect on bone-derived secretory factors. Understanding their important role in cross-organ regulation is of great significance for the treatment of diseases, especially for the elderly people with more than one basic disease.

Effects of Obesity on Bone Healing in Rats

Although the association between periodontitis and obesity is well explored, it is unclear whether obesity is associated with a worse therapeutic outcome after periodontal treatment. The aim of this study was to investigate the effects of obesity on bone healing with and without the application of regeneration-promoting molecules. A standardized bone fenestration-type defect was created over the root of the mandibular first molar in 15 Wistar rats. Ten animals received a high-fat, high-sucrose diet (HFSD), while the remaining five animals were fed a standard diet. During surgery, the fenestration defects from half of the HFSD-fed, i.e., obese animals, were treated with regeneration-promoting molecules (enamel matrix derivative; EMD). After four weeks, bone healing was evaluated by histomorphometry, TRAP staining and immunohistochemistry for RUNX2 and osteopontin. The analyses revealed that the spontaneous healing of the periodontal defects was compromised by obesity. Application of EMD partially compensated for the negative effect of obesity. Nevertheless, EMD-stimulated bone healing in obese animals was not better than the spontaneous healing in the obesity-free control group, indicating that obesity may also inhibit the stimulatory effects of regeneration-promoting molecules. Our results show that obesity can negatively influence bone healing and suggest that bone healing may be compromised in humans.

Relationship between Osteopontin and Bone Mineral Density

Recent studies suggest that osteopontin (OPN) could be used as an early marker for the diagnosis of bone disorders. Considering the contradictory opinions in the literature, the objective of this systematic review is to analyse the current information regarding the relationship between OPN and bone mineral density (BMD), which represents an important process in the development of osteoporosis. We performed a literature search of clinical trials using the PubMed database, published between 1999-2020, and identified 7 studies that were eligible for analysis. The eligibility criteria were based on studies that analysed the relationship between osteopontin and bone mineral density on human subjects. Conclusion: serum OPN levels might be used as a biomarker of the early diagnosis of osteoporosis in postmenopausal women, with or without osteoporotic vertebral fractures.

Avian Eggshell Membrane as a Novel Biomaterial: A Review

The eggshell membrane (ESM), mainly composed of collagen-like proteins, is readily available as a waste product of the egg industry. As a novel biomaterial, ESM is attractive for its applications in the nutraceutical, cosmetic, and pharmaceutical fields. This review provides the main information about the structure and chemical composition of the ESM as well as some approaches for its isolation and solubilization. In addition, the review focuses on the role and performance of bioactive ESM-derived products in various applications, while a detailed literature survey is provided. The evaluation of the safety of ESM is also summarized. Finally, new perspectives regarding the potential of ESM as a novel biomaterial in various engineering fields are discussed. This review provides promising future directions for comprehensive application of ESM.

Inhibition of Caspase-1 Ameliorates Ischemia-Associated Blood-Brain Barrier Dysfunction and Integrity by Suppressing Pyroptosis Activation

Ischemic cerebral infarction represents a significant cause of disability and death worldwide. Caspase-1 is activated by the NLRP3/ASC pathway and inflammasomes, thus triggering pyroptosis, a programmed cell death. In particular, this death is mediated by gasdermin D (GSDMD), which induces secretion of interleukin (IL)-1β and IL-18. Accordingly, inhibition of caspase-1 prevents the development and worsening of multiple neurodegenerative diseases. However, it is not clear whether inhibition of caspase-1 can preserve blood-brain barrier (BBB) integrity following cerebral infarction. This study therefore aimed at understanding the effect of caspase-1 on BBB dysfunction and its underlying mechanisms in permanent middle cerebral artery occlusion (MCAO). Our findings in rat models revealed that expression of caspase-1 was upregulated following MCAO-induced injury in rats. Consequently, pharmacologic inhibition of caspase-1 using vx-765 ameliorated ischemia-induced infarction, neurological deficits, and neuronal injury. Furthermore, inhibition of caspase-1 enhanced the encapsulation rate of pericytes at the ischemic edge, decreased leakage of both Evans Blue (EB) and matrix metalloproteinase (MMP) proteins, and upregulated the levels of tight junctions (TJs) and tissue inhibitors of metalloproteinases (TIMPs) in MCAO-injured rats. This in turn improved the permeability of the BBB. Meanwhile, vx-765 blocked the activation of ischemia-induced pyroptosis and reduced the expression level of inflammatory factors such as caspase-1, NLRP3, ASC, GSDMD, IL-1β, and IL-18. Similarly, vx-765 treatment significantly reduced the expression levels of inflammation-related receptor for advanced glycation end products (RAGE), high-mobility family box 1 (HMGB1), mitogen-activated protein kinase (MAPK), and nuclear factor-κB (NF-κB). Evidently, inhibition of caspase-1 significantly improves ischemia-associated BBB permeability and integrity by suppressing pyroptosis activation and the RAGE/MAPK pathway.

Mechanistic Insight on the Interaction between OPN and Integrin ανβ3 in Osteoarthritis

Osteoarthritis (OA) is a joint disease characterized by cartilage degeneration. Osteopontin (OPN) is involved in the initiation, repair, and maintenance of metabolic homeostasis in normal articular cartilage. This study investigated the role of OPN and its interaction with the integrin ανβ3 receptor in the expression of hyaluronic acid (HA) in OA chondrocytes. Overexpression of OPN significantly increased the expression of integrin ανβ3 and hyaluronic acid synthases (HAS) and synthesis of HA. Depleting OPN in OA chondrocytes showed the opposite trend for integrin alpha;νβ3, HAS, and HA. Nonspecifically and specifically blocking integrin receptor using GRGDSP and integrin ανβ3 antibody downregulated HAS and HA; both were inhibited to similar extents. The expression of HAS and HA was predominantly regulated by the interaction between OPN and integrin ανβ3. Taken together, we have delineated the importance of the OPN/integrin ανβ3/HAS/HA axis in OA and identified OPN as a promising candidate for molecular therapy for use in patients with OA.

Effects of metabolic syndrome on bone health in older adults: the Bushehr Elderly Health (BEH) program

Based on the clinical, BMD, and TBS data of 2380 participants aged ≥ 60 which was gathered during the BEH program, stage II, we showed that MetS was positively associated with BMD, while a negative or no association was observed between MetS and TBS depending on the sex and the adjustment model.

INTRODUCTION

The results of previous reports in regard to the effect of metabolic syndrome (MetS) on bone health are not conclusive. This study aimed to evaluate the association between MetS with bone mineral density (BMD) and trabecular bone score (TBS) as an indicator of bone quantity and quality, respectively.

METHODS

Using a cross-sectional design, this study was carried out based on the data collected during the BEH Program, stage II. MetS was defined according to NCEP-ATP III criteria. BMD (at the lumbar spine and the hip) and lumbar spine TBS were assessed by dual-energy X-ray absorptiometry device.

RESULTS

The data of 2380 participants (women = 1228, men = 1152) aged ≥ 60 were analyzed. In the fully adjusted regression models (including BMI), significant associations between MetS and mean BMD were observed across all locations in men (P values ≤ 0.001) and in the lumbar spine in women (P value = 0.003). In addition, the prevalence of osteoporosis (based on BMD) was significantly lower in those with MetS than those without MetS in both sexes, even after full adjustments (women, OR = 0.707, P value = 0.013; men, OR = 0.563, P value = 0.001). In contrast, in age-adjusted regression analyses, the prevalence of degraded bone microarchitecture (TBS ≤ 1.2) was significantly increased in those with MetS than those without, irrespective of the participants' sex (P values < 0.05). The mean TBS was also negatively associated with MetS in women (β = - 0.075, P value = 0.007) but not in men (β = - 0.052, P value = 0.077), in age-adjusted regression models. However, after including BMI in the adjusted models, all significant associations between TBS values and MetS disappeared.

CONCLUSION

It seems that a positive association exists between MetS and BMD, while MetS is either not associated or negatively correlated with bone quality as measured by TBS.

Myocardin-Related Transcription Factor A (MRTF-A) Regulates the Balance between Adipogenesis and Osteogenesis of Human Adipose Stem Cells

Previous studies have demonstrated that myocardin-related transcription factor A (MRTF-A) generates a link between the dynamics of the actin cytoskeleton and gene expression with its coregulator, serum response factor (SRF). MRTF-A has also been suggested as a regulator of stem cell differentiation. However, the role of MRTF-A in human mesenchymal stem cell differentiation remains understudied. We aimed to elucidate whether MRTF-A is a potential regulator of human adipose stem cell (hASC) differentiation towards adipogenic and osteogenic lineages. To study the role of MRTF-A activity in the differentiation process, hASCs were cultured in adipogenic and osteogenic media supplemented with inhibitor molecules CCG-1423 or CCG-100602 that have been shown to block the expression of MRTF-A/SRF-activated genes. Our results of image-based quantification of Oil Red O stained lipid droplets and perilipin 1 staining denote that MRTF-A inhibition enhanced the adipogenic differentiation. On the contrary, MRTF-A inhibition led to diminished activity of an early osteogenic marker alkaline phosphatase, and export of extracellular matrix (ECM) proteins collagen type I and osteopontin. Also, quantitative Alizarin Red staining representing ECM mineralization was significantly decreased under MRTF-A inhibition. Image-based analysis of Phalloidin staining revealed that MRTF-A inhibition reduced the F-actin formation and parallel orientation of the actin filaments. Additionally, MRTF-A inhibition affected the protein amounts of α-smooth muscle actin (α-SMA), myosin light chain (MLC), and phosphorylated MLC suggesting that MRTF-A would regulate differentiation through SRF activity. Our results strongly indicate that MRTF-A is an important regulator of the balance between osteogenesis and adipogenesis of hASCs through its role in mediating the cytoskeletal dynamics. These results provide MRTF-A as a new interesting target for guiding the stem cell differentiation in tissue engineering applications for regenerative medicine.

Topographical regulation of stem cell differentiation by plant-derived micro/nanostructures

This study examines the osteogenic differentiation promotion effect of micro/nanostructures of raffia on human adipose-derived stem cells to confirm the potential application of plant-derived micro/nanotopographies in tissue regeneration. The results confirm that the nanorod array on the front surface and the honeycomb-like microstructure on the back surface of raffia can not only regulate the adhesion, spreading, and migration of stem cells but also promote the osteogenic differentiation of the stem cells at a subsequent stage of cell culture. The osteocalcin expressions by the 21-day cultured cells on the front and back surfaces of raffia were 55-fold and 36-fold higher compared to the expression on a tissue culture plate. This indicates that plant-derived micro/nanotopographies can significantly promote stem cell differentiation. Furthermore, a general strategy for the application of plant-derived materials to stem-cell differentiation and bone-tissue engineering is suggested.

Histological, Histochemical and Immunohistochemical Evaluation of the Role of Bone Marrow-Derived Mesenchymal Stem Cells on the Structure of Periodontal Tissues in Carbimazole-Treated Albino Rats

OBJECTIVE

To elucidate the role of bone marrow-mesenchymal stem cells (BM-MSCs) on the structure of periodontal tissues in carbimazole (antithyroid drug) treated rats at different durations.

DESIGN

28 albino rats were divided into: Group I: received distilled water. Group II: received therapeutic dose of carbimazole. Group III: received carbimazole then single injection of BM-MSCs by the end of 3^rd week. Group IV: received carbimazole and single injection of BM-MSCs at the beginning of the experiment. Specimens were examined by light microscope. New collagen and β-catenin-immunoreactivity area% were assessed histomorphometrically, and statistically using ANOVA test.

RESULTS

Histological examination revealed normal periodontal tissues structure in Groups I & IV. Group II showed disorganized periodontal ligament fibers and different stainability of cementum and alveolar bone. Group III illustrated dense periodontal ligament fibers, normal stainability of cementum and most of alveolar bone. Masson's trichrome results of Groups I & IV illustrated large areas of new collagen in periodontal ligament, old collagen in cementum and intermingled old and new collagen in alveolar bone. Group II showed old collagen. Group III revealed only new collagen. β-catenin-immunoreactivity was strong in Groups I & IV, negative in Group II and moderate in Group III. Statistically, Group III showed highest mean of new collagen area% followed by Groups I, IV and II respectively. Highest mean of β-catenin-immunoreactivity area% was for Group I followed by Groups IV, III and II respectively.

CONCLUSIONS

Carbimazole has damaging effects and BM-MSCs are capable to mend these destructive outcomes in time dependent manner.

Role of fibronectin in chronic venous diseases: A review

Fibronectin (FN) circulating in the blood and produced by cells provides the basis of the extracellular matrix (ECM) formed in healing acute wounds. The time-dependent deposition of FN by macrophages, its synthesis by fibroblasts and myofibroblasts, and later degradation in the remodeled granulation tissue are a prerequisite for successful healing of wounds. However, the pattern of FN expression and deposition in skin lesions is disturbed. The degradation of the ECM components including FN in varicose veins prevails over ECM synthesis and deposition. FN is inconspicuous in the fibrotic lesions in lipodermatosclerosis, while tenascin-C containing FN-like peptide sequences are prominent. FN is produced in large amounts by fibroblasts at the edge of venous ulcers but FN deposition at the wound bed is impaired. Both the proteolytic environment in the wounds and the changed function of the ulcer fibroblasts may be responsible for the poor healing of venous ulcers. The aim of this review is to describe the current knowledge of FN pathophysiology in chronic venous diseases. In view of the fact that FN plays a crucial role in organizing the ECM, further research focused on FN metabolism in venous diseases may bring results applicable to the treatment of the diseases.

Multilineage Differentiation Potential of Human Dental Pulp Stem Cells-Impact of 3D and Hypoxic Environment on Osteogenesis In Vitro

Human dental pulp harbours unique stem cell population exhibiting mesenchymal stem/stromal cell (MSC) characteristics. This study aimed to analyse the differentiation potential and other essential functional and morphological features of dental pulp stem cells (DPSCs) in comparison with Wharton’s jelly-derived MSCs from the umbilical cord (UC-MSCs), and to evaluate the osteogenic differentiation of DPSCs in 3D culture with a hypoxic microenvironment resembling the stem cell niche. Human DPSCs as well as UC-MSCs were isolated from primary human tissues and were subjected to a series of experiments. We established a multiantigenic profile of DPSCs with CD45⁻/CD14⁻/CD34⁻/CD29⁺/CD44⁺/CD73⁺/CD90⁺/CD105⁺/Stro-1⁺/HLA-DR⁻ (using flow cytometry) and confirmed their tri-lineage osteogenic, chondrogenic, and adipogenic differentiation potential (using qRT-PCR and histochemical staining) in comparison with the UC-MSCs. The results also demonstrated the potency of DPSCs to differentiate into osteoblasts in vitro. Moreover, we showed that the DPSCs exhibit limited cardiomyogenic and endothelial differentiation potential. Decreased proliferation and metabolic activity as well as increased osteogenic differentiation of DPSCs in vitro, attributed to 3D cell encapsulation and low oxygen concentration, were also observed. DPSCs exhibiting elevated osteogenic potential may serve as potential candidates for a cell-based product for advanced therapy, particularly for bone repair. Novel tissue engineering approaches combining DPSCs, 3D biomaterial scaffolds, and other stimulating chemical factors may represent innovative strategies for pro-regenerative therapies.

The Importance of Breast Adipose Tissue in Breast Cancer

Adipose tissue is a complex endocrine organ, with a role in obesity and cancer. Adipose tissue is generally linked to excessive body fat, and it is well known that the female breast is rich in adipose tissue. Hence, one can wonder: what is the role of adipose tissue in the breast and why is it required? Adipose tissue as an organ consists of adipocytes, an extracellular matrix (ECM) and immune cells, with a significant role in the dynamics of breast changes throughout the life span of a female breast from puberty, pregnancy, lactation and involution. In this review, we will discuss the importance of breast adipose tissue in breast development and its involvement in breast changes happening during pregnancy, lactation and involution. We will focus on understanding the biology of breast adipose tissue, with an overview on its involvement in the various steps of breast cancer development and progression. The interaction between the breast adipose tissue surrounding cancer cells and vice-versa modifies the tumor microenvironment in favor of cancer. Understanding this mutual interaction and the role of breast adipose tissue in the tumor microenvironment could potentially raise the possibility of overcoming breast adipose tissue mediated resistance to therapies and finding novel candidates to target breast cancer.

Retinoic Acid Signal Negatively Regulates Osteo/Odontogenic Differentiation of Dental Pulp Stem Cells

Retinoic acid (RA) signal is involved in tooth development and osteogenic differentiation of mesenchymal stem cells (MSCs). Dental pulp stem cells (DPSCs) are one of the useful MSCs in tissue regeneration. However, the function of RA in osteo/odontogenic differentiation of DPSCs remains unclear. Here, we investigated the expression pattern of RA in miniature pig tooth germ and intervened in the RA signal during osteo/odontogenic differentiation of human DPSCs. Deciduous canine (DC) germs of miniature pigs were observed morphologically, and the expression patterns of RA were studied by in situ hybridization (ISH). Human DPSCs were isolated and cultured in osteogenic induction medium with or without RA or BMS 493, an inverse agonist of the pan-retinoic acid receptors (pan-RARs). Alkaline phosphatase (ALP) activity assays, alizarin red staining, quantitative calcium analysis, CCK8 assay, osteogenesis-related gene expression, and in vivo transplantation were conducted to determine the osteo/odontogenic differentiation potential and proliferation potential of DPSCs. We found that the expression of RARβ and CRABP2 decreased during crown calcification of DCs of miniature pigs. Activation of RA signal in vitro inhibited ALP activities and mineralization of human DPSCs and decreased the mRNA expression of ALP, osteocalcin, osteopontin, and a transcription factor, osterix. With BMS 493 treatment, the results were opposite. Interference in RA signal decreased the proliferation of DPSCs. In vivo transplantation experiments suggested that osteo/odontogenic differentiation potential of DPSCs was enhanced by inversing RA signal. Our results demonstrated that downregulation of RA signal promoted osteo/odontogenic differentiation of DPSCs and indicated a potential target pathway to improve tissue regeneration.

Three dimensional microcarrier system in mesenchymal stem cell culture: a systematic review

Stem cell-based regenerative medicine is a promising approach for tissue reconstruction. However, a large number of cells are needed in a typical clinical study, where conventional monolayer cultures might pose a limitation for scale-up. The purpose of this review was to systematically assess the application of microcarriers in Mesenchymal Stem Cell cultures. A comprehensive search was conducted in Medline via Ebscohost, Pubmed, and Scopus, and relevant studies published between 2015 and 2019 were selected. The literature search identified 53 related studies, but only 14 articles met the inclusion criteria. These include 7 utilised commercially available microcarriers, while the rest were formulated based on different surface characteristics, all of which are discussed in this review. Current applications of microcarriers were focused on MSC expansion and induction of MSCs into different lineages. These studies demonstrated that MSCs could proliferate in a microcarrier culture system in-fold compared to monolayer cultures, and the culture system could simulate a three-dimensional environment which induces cell differentiation. However, detailed studies are still required before this system were to be adapted into the scale of GMP manufacturing.

Mesoporous Hydroxyapatite/Chitosan Loaded With Recombinant-Human Amelogenin Could Enhance Antibacterial Effect and Promote Periodontal Regeneration

The recovery of impaired periodontium is still a challenge to the treatment of periodontitis. This study was the first to apply the mesoporous hydroxyapatites/chitosan (mHA/CS) composite scaffold to periodontal regeneration. The aim of our study is to evaluate the biological effects of mesoporous hydroxyapatite/chitosan (mHA/CS) loaded with recombinant human amelogenin (rhAm) on periodontal regeneration. The physicochemical properties of mHA/CS scaffolds were examined by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analysis. Then, the biological effects of the mHA/CS loaded with rhAm were evaluated, including antibacterial effect, controlled-release capacity, osteogenic and cementogenic effects in vitro and in vivo. The antibacterial effect was tested on 1.5 mg/mL CS; 3 mg/mL mHA; 2.25 mg/mL mHA/CS; 4.5 mg/mL mHA/CS and 20 μg/mL rhAm. Tryptic Soy Broth culture medium was used as a baseline control. Osteogenic effect of rhAm (20 μg/mL rhAm), mHA/CS (4.5 mg/mL mHA/CS), and mHA/CS-rhAm (4.5 mg/mL mHA/CS and 20 μg/mL rhAm) on human periodontal ligament cells (hPDLCs) was evaluated in osteogenic media. The hPDLCs treated either with osteogenic media or Dulbecco's modified Eagle's medium (DMEM) alone were used as the baseline control. In the animal model, 4-week-old nude mice (BALB/c) (n = 6) implanted with root slices subcutaneously were used to observe the cementogenic effect in vivo. The root slices were treated with rhAm (20 μg/mL rhAm), mHA/CS (4.5 mg/mL mHA/CS), and mHA/CS-rhAm (4.5 mg/mL mHA/CS and 20 μg/mL rhAm). The root slices treated with osteogenic medium alone were used as the baseline control. The analyses showed that the mHA/CS particles were 2 μm in diameter and had a uniform pore size. The mesoporous structure was 7 nm in diameter and its surface area was 33.95 m²/g. The scaffold exhibited antibacterial effects against Fusobacterium nucleatum and Porphyromonas gingivalis. The mHA/CS scaffold sustainably released rhAm. The mHA/CS loaded with 20 μg/mL rhAm upregulated ALP activity, the expression levels of osteogenesis-related genes and proteins in vitro. Additionally, it promoted the formation of cementum-like tissue in vivo. Our findings suggest that mHA/CS loaded with 20 μg/mL rhAm could inhibit the growth of periodontal pathogens and promote the formation of bone and cementum-like tissue.

RGD-functionalized supported lipid bilayers modulate pre-osteoblast adherence and promote osteogenic differentiation

Biomaterial integration into bone requires optimal surface conditions to promote osteoprogenitor behavior, which is affected by integrin-binding via arginine-glycine-aspartate (RGD). RGD-functionalized supported lipid bilayers (SLBs) might be interesting as biomaterial coating in bone regeneration, because they allow integration of proteins, for example, growth factors, cytokines, and/or antibacterial agents. Since it is unknown whether and how they affect osteoprogenitor adhesion and differentiation, the aim was to investigate adhesion, focal adhesion formation, morphology, proliferation, and osteogenic potential of pre-osteoblasts cultured on RGD-functionalized SLBs compared to unfunctionalized SLBs and poly-l-lysine (PLL). After 17 hr, pre-osteoblast density on SLBs without or with RGD was similar, but lower than on PLL. Cell surface area, elongation, and number and size of phospho-paxillin clusters were also similar. Cells on SLBs without or with RGD were smaller, more elongated, and had less and smaller phospho-paxillin clusters than on PLL. OPN expression was increased on SLBs with RGD compared to PLL. Moreover, after 1 week, COL1a1 expression was increased on SLBs without or with RGD. In conclusion, pre-osteoblast adhesion and enhanced differentiation were realized for the first time on RGD-functionalized SLBs, pointing to a new horizon in the management of bone regeneration using biomaterials. Together with SLBs nonfouling nature and the possibility of adjusting SLB fluidity and peptide content make SLBs highly promising as substrate to develop innovative biomimetic coatings for biomaterials in bone regeneration.

Role of growth factors in hematopoietic stem cell niche

Hematopoietic stem cells (HSCs) produce new blood cells everyday throughout life, which is maintained by the self-renewal and differentiation ability of HSCs. This is not controlled by the HSCs alone, but rather by the complex and exquisite microenvironment surrounding the HSCs, which is called the bone marrow niche and consists of various bone marrow cells, growth factors, and cytokines. It is essential to understand the characteristic role of the stem cell niche and the growth factors in the niche formation. In this review, we describe the role of the bone marrow niche and factors for niche homeostasis, and also summarize the latest research related to stem cell niche.

Bone marrow adipose tissue does not express UCP1 during development or adrenergic-induced remodeling

Adipocytes within the skeleton are collectively termed bone marrow adipose tissue (BMAT). BMAT contributes to peripheral and local metabolism, however, its capacity for cell-autonomous expression of uncoupling protein 1 (UCP1), a biomarker of beige and brown adipogenesis, remains unclear. To overcome this, Ucp1-Cre was used to drive diphtheria toxin expression in cells expressing UCP1 (Ucp1Cre+/DTA+). Despite loss of brown adipose tissue, BMAT volume was not reduced in Ucp1Cre+/DTA+ mice. Comparably, in mTmG reporter mice (Ucp1Cre+/mTmG+), Ucp1-Cre expression was absent from BMAT in young (3-weeks) and mature (16-weeks) male and female mice. Further, β3-agonist stimulation failed to induce Ucp1-Cre expression in BMAT. This demonstrates that BMAT adipocytes are not UCP1-expressing beige/brown adipocytes. Thus, to identify novel and emerging roles for BMAT adipocytes in skeletal and whole-body homeostasis, we performed gene enrichment analysis of microarray data from adipose tissues of adult rabbits. Pathway analysis revealed genetic evidence for differences in BMAT including insulin resistance, decreased fatty acid metabolism, and enhanced contributions to local processes including bone mineral density through candidate genes such as osteopontin. In sum, this supports a paradigm by which BMAT adipocytes are a unique subpopulation that is specialized to support cells within the skeletal and hematopoietic niche.

NF-κB Signaling Pathways in Osteoarthritic Cartilage Destruction

Osteoarthritis (OA) is a type of joint disease associated with wear and tear, inflammation, and aging. Mechanical stress along with synovial inflammation promotes the degradation of the extracellular matrix in the cartilage, leading to the breakdown of joint cartilage. The nuclear factor-kappaB (NF-κB) transcription factor has long been recognized as a disease-contributing factor and, thus, has become a therapeutic target for OA. Because NF-κB is a versatile and multi-functional transcription factor involved in various biological processes, a comprehensive understanding of the functions or regulation of NF-κB in the OA pathology will aid in the development of targeted therapeutic strategies to protect the cartilage from OA damage and reduce the risk of potential side-effects. In this review, we discuss the roles of NF-κB in OA chondrocytes and related signaling pathways, including recent findings, to better understand pathological cartilage remodeling and provide potential therapeutic targets that can interfere with NF-κB signaling for OA treatment.

Osteopontin Promotes Colorectal Cancer Cell Invasion and the Stem Cell-Like Properties through the PI3K-AKT-GSK/3β-β/Catenin Pathway

BACKGROUND Osteopontin (OPN) is a molecule expressed in numerous cancers including colorectal cancer (CRC) that correlates disease progression. The interaction of OPN that promotes CRC cell migration, invasion, and cancer stem-like cells (CSCs) have not been elucidated. Hence, we aimed to investigate the mechanisms that might be involved. MATERIAL AND METHODS Expression of OPN in tumor tissues derived from patients was monitored with real-time quantitative polymerase chain reaction and western blot. Wound healing and Transwell assay were used to test the differences in migration and invasion in an OPN enriched environment and OPN knockdown condition. Aldehyde dehydrogenase 1 (ALDH1) positive stem cells were isolated using fluorescence-activated cell sorting (FACS) following the protocol of the ALDEFLUOR™ kit. The expression of protein participation in the PI3K-Akt-GSK/3ß-ß/catenin pathway was detected by western blot. RESULTS OPN exhibited increased levels in CRC tumor tissue compared with non-tumor normal tissue and the high level of which correlated with lymphatic metastasis and late TNM stage. Additional rhOPN co-cultured low-expression CRC cells demonstrated more aggressive capability of proliferation, migration, and invasion. For knockdown of OPN in high-expression CRC cells, the bioactivities of proliferation, migration, and invasion were significantly inhibited. Interestingly, the percentage of ALDH1 labeled stem cells was dramatically decreased by OPN inhibition. The phosphorylation of PI3K-Akt-GSK/3ß-ß/catenin pathway was involved in the OPN signaling. Furthermore, Ly294002, a specific PI3K inhibitor, can reverse the promotion of bioactivities and stem cell proportion among rhOPN treated CRC cells. CONCLUSIONS OPN promoted cell proliferation, migration, and invasion, and was accompanied by upregulation of ALDH1-positive CSC in CRC through activation of PI3K-Akt-GSK/3ß-ß/catenin pathway.

Bone metabolism markers are associated with neck circumference in adult Arab women

The study aimed to determine whether neck circumference is associated with bone metabolism markers among adult Arab women and found modest but significant associations with bone resorption markers, suggesting that neck circumference, a surrogate measure of upper subcutaneous fat, influences bone turnover expression among adult females.

INTRODUCTION

Body fat distribution is associated with decreased bone resorption and neck circumference (NC), a surrogate measure for upper body fat, has never been tested as a marker that can reflect bone turnover. This is the first study aimed to analyze the associations between NC and several bone biomarkers among adult Saudi women.

METHODS

This cross-sectional study included a total of 265 middle-aged Saudi women [86 non-obese (mean age 52.7 ± 8.1; mean BMI 26.9 ± 2.3) and 179 obese (mean age 50.6 ± 7.5; mean BMI 35.7 ± 4.5)] recruited from primary care centers in Riyadh, Saudi Arabia. Anthropometrics included BMI, NC, waist and hip circumferences, total body fat percentage (%), and blood pressure. Biochemical parameters included glucose and lipid profile which were measured routinely. Serum levels of 25(OH) D, parathyroid hormone, RANKl, sclerostin, C-terminal telopeptide of collagen I (CTX-I), Dkk1, IL1β, osteoprotegerin, osteopontin, and osteocalcin were measured using commercially available assays.

RESULTS

In all groups, NC was inversely associated with PTH (R = - 0.22; p < 0.05) and positively associated with osteoprotegerin (R = 0.20; p < 0.05) even after adjustments for age and BMI. Using all anthropometric indices as independent variables showed that only NC explained the variance perceived in CTX-I (p = 0.049). In the non-obese, waist-hip ratio (WHR) was significantly associated with sclerostin (R = 0.40; p < 0.05) and body fat was significantly associated with osteopontin (R = 0.42; p < 0.05).

CONCLUSION

NC is modestly but significantly associated with bone biomarkers, particularly the bone resorption markers, among adult Arab women. The present findings highlight the importance of NC as measure of upper body subcutaneous fat in influencing bone biomarker expression in adult females.

ALVEOLAR BONE PATTERN AND SALIVARY LEPTIN LEVELS AMONG PREMENOPAUSAL OBESE WOMEN

Background:

Systemic bone loss may lead to more severe periodontal destruction, decreasing local bone mineral density.

Aim:

A cross-sectional designed was performed to study associations among alveolar bone pattern, salivary leptin concentrations, and clinical periodontal status in premenopausal obese and eutrophic women.

Methods:

Thirty morbid obese (G1) and 30 normal-weight (G2) women were included. Anthropometric and periodontal measurements (probing depth - PD, clinical attachment levels - CAL, presence of calculus, bleeding on probing -BOP, and plaque accumulation) were assessed. OHIP-14 was used for assessment of oral health impact on quality of life. Panoramic radiography was used to obtain the panoramic mandibular index (PMI), mandibular cortical index (MCI), and mental index (MI). Intraoral periapical (PA) radiography was taken to measure the total trabecular bone volume. Leptin was measured in saliva of fasted overnight women.

Results:

Groups 1 and 2 differed in all anthropometric aspects, but height. Pocket depth, calculus, BOP, and plaque index were worse in G1. No differences between groups were found considering OHIP. Normal-weight subjects showed higher proportion of dense bone trabeculae than obese subjects for pre-molars, but not for molars. Mental and panoramic mandibular indexes did not differ and were in normal level. Leptin concentration was dependent only on BMI.

Conclusion:

Obesity affected the periodontal conditions, the alveolar bone pattern, and the salivary leptin concentration.

The role of physical forces in osteoclastogenesis

The movements of life at every level from organs, tissues, cells to sub-cells, are all conducted in certain physical environments. In the human body, skeletal tissue among all connective tissues is influenced the most by physical forces. Studying the biological behavior of bone cells under different physical environments is helpful in further understanding bone homeostasis and metabolism. Among all bone cells, osteoclast (OC) and OC steered bone remodeling is one of the key points in bone metabolism. In the past few decades, people's understanding of OC was mostly limited to its involvement of bone resorption under physiological and pathological conditions. However, more and more studies started to focus on how physical forces affect the formation and differentiation of OC. This review tries to illustrate the knowledge up to date about how osteoclastogenesis is regulated by physical forces through direct and indirect ways, including fluid shear force, compressive force, and microgravity. The direct way describes the straightforward effects produced by different forces in osteoclastogenesis, whereas the indirect way describes the effects of different forces in osteoclastogenesis through regulation of other bone cells when a certain force is applied. Molecular mechanisms were analyzed and reviewed in both direct and indirect regulation by different forces. Finally, we discussed the status quo and tendency of related research, as well as other unresolved issues, and some future prospects.

Comparative Secretome Analyses of Primary Murine White and Brown Adipocytes Reveal Novel Adipokines

The adipose organ, including white and brown adipose tissues, is an important player in systemic energy homeostasis, storing excess energy in form of lipids while releasing energy upon various energy demands. Recent studies have demonstrated that white and brown adipocytes also function as endocrine cells and regulate systemic metabolism by secreting factors that act locally and systemically. However, a comparative proteomic analysis of secreted factors from white and brown adipocytes and their responsiveness to adrenergic stimulation has not been reported yet. Therefore, we studied and compared the secretome of white and brown adipocytes, with and without norepinephrine (NE) stimulation. Our results reveal that carbohydrate-metabolism-regulating proteins are preferably secreted from white adipocytes, while brown adipocytes predominantly secrete a large variety of proteins. Upon NE stimulation, an increased secretion of known adipokines is favored by white adipocytes while brown adipocytes secreted higher amounts of novel adipokines. Furthermore, the secretory response between NE-stimulated and basal state was multifaceted addressing lipid and glucose metabolism, adipogenesis, and antioxidative reactions. Intriguingly, NE stimulation drastically changed the secretome in brown adipocytes. In conclusion, our study provides a comprehensive catalogue of novel adipokine candidates secreted from white and brown adipocytes with many of them responsive to NE. Given the beneficial effects of brown adipose tissue activation on its endocrine function and systemic metabolism, this study provides an archive of novel batokine candidates and biomarkers for activated brown adipose tissue.

Vitamin D deficiency increases blood-brain barrier dysfunction after ischemic stroke in male rats

Because vitamin D hormone deficiency (VDH^def) can worsen severity and outcome for ischemic stroke, we examined the role of VDH in maintaining blood-brain-barrier (BBB integrity) in a rat model of stroke. In most types of stroke, the BBB is markedly compromised, potentially leading to a cascade of injury processes and functional deficits, so we examined a number of biomarkers associated with BBB disruption to determine whether VDH deficiency would further compromise the BBB following a stroke. Male Wistar rats were randomly assigned to one of two diet cohorts, VDH-sufficient (VDH^suf) and VDH^def. The VDH^suf group was fed standard rat chow and the VDH^def group got a VDH-null version of the same diet for 8 weeks. Animals from both cohorts were subjected to transient middle cerebral artery occlusion (tMCAO) surgery, killed at 72 h post-stroke, and their brains evaluated for BBB permeability and injury severity using expression of immunoglobulin (IgG), matrix metalloproteinase-9 (MMP-9) activity and alteration of tight junction (TJ) proteins as markers of BBB disruption. We also evaluated modulation of glucose transporter-1 (GLUT1), osteopontin (OPN), β-catenin and vitamin D receptor (VDR) expression in VDH^suf and VDH^def subjects. At the time of MCAO, rats on the VDH^def diet had circulating VDH levels one-fourth that of rats fed control chow. IgG extravasation after MCAO, indicating more severe BBB injury, was significantly higher in the MCAO+VDH^def than the MCAO+VDH^suf rats. Following MCAO, expression of MMP-9, GLUT1, VDR and OPN increased and the TJ proteins occludin and claudin-5 decreased significantly in the VDH^def compared to the VDH^suf group. We also observed significantly lower expression of β-catenin in the MCAO group of both VDH^suf and VDH^def rats. Under these conditions, VDH deficiency itself can compromise the BBB. We think that low serum VDH levels are likely to complicate stroke severity and its chronic consequences.

Osteopontin levels in plasma, muscles, and bone in patient with non-healing diabetic foot ulcers: A new player in wound healing process?

BACKGROUND

The present study was designed to investigate the impact of osteopontin (OPN) in different tissue (e.g., plasma, muscles and bone) on amputation rate (in-hospital and during one year follow-up) for non-healing diabetic foot ulcers (DFUs).

METHODS

This pilot study consisted of 30 diabetic patients, hospitalized due to non-healing DFUs. Patients were divided into two groups: Group 1 included 14 patients who underwent limb-preserved debridement procedure without amputation; Group 2 included 16 subjects who underwent amputation. Additionally, recurrent amputation rate during 1 year follow-up was investigated.

RESULTS

Plasma OPN was higher and bone OPN was lower in Group 2 compared to Group 1 (p = 0.016 and p = 0.004, respectively). In the logistic regression analysis, bone OPN emerged as a significant independent predictor of amputation (OR = 0.042, 95% CI 0.003-0.699, p = 0.027). Plasma OPN was also associated with amputation such that each unit increase in plasma OPN was associated with an increase in odds of amputation of 17.7% (95% CI 0.997-1.388, p = 0.045). During 1 year follow-up 11 patients underwent recurrent amputation. Plasma OPN were higher and bone osteopontin was lower in patients who underwent amputation compared to patients who did not need amputation at one year follow-up. However, in GLM analysis bone OPN was only marginally associated with one year amputation (OR 0.001, 95% CI 0.000-2.0, p = 0.076).

CONCLUSIONS

Decreased levels of OPN in bone and increased plasma OPN are independently associated with in-hospital amputation. Consequently, plasma OPN may be relevant in the routine assessment of amputation risk in this patient population.

The impact of photofunctionalized gold nanoparticles on osseointegration

OBJECTIVES

The aims of this study were to create a new surface topography using simulated body fluids (SBF) and Gold Nanoparticles (GNPs) and then to assess the influence of UV Photofunctionalization (PhF) on the osteogenic capacity of these surfaces.

MATERIALS AND METHODS

Titanium plates were divided into six groups All were acid etched with 67% Sulfuric acid, 4 were immersed in SBF and 2 of these were treated with 10 nm GNPs. Half of the TiO2 plates were photofunctionalized to be compared with the non-PhF ones. Rat's bone marrow stem cells were seeded into the plates and then CCK8 assay, cell viability assay, immunofluorescence, and Scanning electron microscopy (SEM) were done after 24 hours. Gene expression analysis was done using real time quantitative PCR (qPCR) one week later to check for the mRNA expression of Collagen-1, Osteopontin and Osteocalcin. Alkaline phosphatase (ALP) activity was assessed after 2 weeks of cell seeding.

RESULTS

Our new topography has shown remarkable osteogenic potential. The new surface was the most biocompatible, and the 10 nm GNPs did not show any cytotoxicity. There was a significant increase in bioactivity, enhanced gene expressions and ALP activity.

CONCLUSIONS

GNPs enhances osteogenic differentiation of stem cells and Photofunctionalizing GNPs highly increases this. We have further created a novel highly efficient topography which highly enhances the speed and extent of osseointegration. This may have great potential for improving treatment outcomes for implant, maxillofacial as well as orthopedic patients.

Combination of biomarkers of vascular calcification and sTWEAK to predict cardiovascular events in chronic kidney disease

BACKGROUND AND AIMS

Vascular calcification (VC) and atherosclerosis are associated with an increased cardiovascular morbimortality in chronic kidney disease (CKD). Osteoprotegerin (OPG) and osteopontin (OPN) are involved in both VC and CKD. Soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) has been related to cardiovascular disease. We hypothesized that OPG, OPN and sTWEAK levels may be associated with a higher prevalence of cardiovascular outcomes in patients with CKD.

METHODS

The presence of calcified or non-calcified atherosclerotic plaques was assessed in 1043 stage 3 to 5D CKD patients from The NEFRONA Study. Biochemical measurements and OPG, OPN and sTWEAK serum levels were analyzed. Patients were followed for cardiovascular outcomes (41 ± 16 months).

RESULTS

At recruitment, 26% of CKD patients had VC. The adjusted odds ratios for having VC were 2.22 (1.32-3.75); p=.003 for OPG, and 0.45 (0.24-0.84); p=.01 for sTWEAK concentrations. After follow-up, 95 CV events occurred. In a Cox model, patients with OPG or OPN above and sTWEAK below their optimal cut-off points had an adjusted higher risk of cardiovascular events [HR: 2.10 (1.49-3.90); p=.02; 1.65 (1.02-2.65); p=.04; 2.05 (1.28-3.29), p=.003; respectively]. When CKD patients were grouped according to the number of biomarkers above (OPG and OPN) or below (sTWEAK) their cut-off points, the combination of these biomarkers showed the highest risk for cardiovascular events [HR: 9.46 (3.80-23.5) p < .001]. A composite score of these three biomarkers increased the C-statistic and net reclassification index beyond conventional risk factors and VC.

CONCLUSIONS

The combination of OPG, OPN and sTWEAK increased the predictability of cardiovascular outcomes.

Fibroblast growth factor 21 ameliorates vascular calcification by inhibiting osteogenic transition in vitamin D3 plus nicotine-treated rats

FGF21, a special member of FGF superfamily, has been proven to have pleiotropic metabolic effects and many potential therapeutic action in various metabolic disorders. Vascular calcification (VC), a perplexing clinical issue, is a major risk factor for many cardiovascular diseases, especially for patients with some metabolic diseases. However, the role of FGF21 on VC in vivo remains unclear. Thus, in this study, we observed the effect and mechanism of FGF21 on VC induced by vitamin D3 plus nicotine (VDN) treated rats. After four weeks' treatment, the calcium overload is mainly manifested in the increased blood pressure, aortic calcium content and ALP activity. Also, the HE and Alizarin-red S staining showed the structural damage of calcified vessel walls. In addition, the level of endogenous FGF21/β-Klotho/FGFR1 axis was up-regulated in the aortas of VC rats. Furthermore, exogenous FGF21 treatment significantly ameliorated the aortic injury and calcification in VC rats, and the level of β-Klotho and FGFR1 were furtherly increase. Moreover, FGF21 inhibited the osteogenic transition of VSMCs by down-regulating the expression of bone-associated proteins such as osteopontin (OPN), osteocalcin (OCN) and bone morphogenetic protein-2 (BMP-2), together with restored the expression of SM22α and SM α-actin, which are two of lineage markers in VSMCs. We provide the first evidence that FGF21 can inhibit the development of VC by inhibiting the osteogenic transition of VSMCs in rats. FGF21 might be an efficient endogenous vasoprotective factor for calcification.

Role of osteopontin and its regulation in pancreatic islet

Osteopontin (OPN) is involved in various physiological processes and also implicated in multiple pathological states. It has been suggested that OPN may have a role in type 2 diabetes (T2D) by protecting pancreatic islets and interaction with incretins. However, the regulation and function of OPN in islets, especially in humans, remains largely unexplored. In this study, we performed our investigations on both diabetic mouse model SUR1-E1506K+/+ and islets from human donors. We demonstrated that OPN protein, secretion and gene expression was elevated in the diabetic SUR1-E1506K+/+ islets. We also showed that high glucose and incretins simultaneously stimulated islet OPN secretion. In islets from human cadaver donors, OPN gene expression was elevated in diabetic islets, and externally added OPN significantly increased glucose-stimulated insulin secretion (GSIS) from diabetic but not normal glycemic donors. The increase in GSIS by OPN in diabetic human islets was Ca²⁺ dependent, which was abolished by Ca²⁺-channel inhibitor isradipine. Furthermore, we also confirmed that OPN promoted cell metabolic activity when challenged by high glucose. These observations provided evidence on the protective role of OPN in pancreatic islets under diabetic condition, and may point to novel therapeutic targets for islet protection in T2D.

Hypoxia and Redox Signaling on Extracellular Matrix Remodeling: From Mechanisms to Pathological Implications

SIGNIFICANCE

The extracellular matrix (ECM) is an essential modulator of cell behavior that influences tissue organization. It has a strong relevance in homeostasis and translational implications for human disease. In addition to ECM structural proteins, matricellular proteins are important regulators of the ECM that are involved in a myriad of different pathologies. Recent Advances: Biochemical studies, animal models, and study of human diseases have contributed to the knowledge of molecular mechanisms involved in remodeling of the ECM, both in homeostasis and disease. Some of them might help in the development of new therapeutic strategies. This review aims to review what is known about some of the most studied matricellular proteins and their regulation by hypoxia and redox signaling, as well as the pathological implications of such regulation.

CRITICAL ISSUES

Matricellular proteins have complex regulatory functions and are modulated by hypoxia and redox signaling through diverse mechanisms, in some cases with controversial effects that can be cell or tissue specific and context dependent. Therefore, a better understanding of these regulatory processes would be of great benefit and will open new avenues of considerable therapeutic potential.

FUTURE DIRECTIONS

Characterizing the specific molecular mechanisms that modulate matricellular proteins in pathological processes that involve hypoxia and redox signaling warrants additional consideration to harness the potential therapeutic value of these regulatory proteins. Antioxid. Redox Signal. 27, 802-822.

Improvement of Bone Physiology and Life Quality Due to Association of Risedronate and Anastrozole

The endocrine therapy is the new frontiers of many breast cancers hormone sensitive. Hormone therapy for treating women with hormone receptor-positive cancer suppresses breast cancer growth either by reducing estrogen synthesis or by interfering with the action of estrogen within tumor cells. In this prospective randomized observational study we investigate the effect of adjuvant anastrozole in monotherapy or associated with risedronate on bone physiology and quality of life in postmenopausal, hormone-sensitive early breast cancer women at mild to moderate risk of fragility fractures.

Methods : 84 women were randomly assigned to receive anastrozole alone (group A) or anastrozole plus oral risedronate (group A+R). At baseline and after 24 months lumbar spine (LS) and femoral neck (FN) BMD were evaluated with dual-energy x-ray absorptiometry and health-related quality of life (HRQoL) was examined using the short-form healthy survey.

Results : After 24 months, the group A+R has showed a significant increase in T-score for LS (p < 0.05) and for FN (p < 0.05) whereas women of group A had a statistically significant rate of bone loss both in LS T-score (p < 0.05) and in FN (p < 0.05). A significant change in T-score BMD was seen for group A+R compared with group A at the LS (p = 0.04) and at FN (p = 0.04). Finally, group A+R showed an overall significant improvement of health profile (SF-36) in group A (p = 0.03).

Conclusion : Postmenopausal breast cancer women with osteopenia during treatment with anastrozole have considerable risk of developing osteoporosis during the first 2 years; preventive measures such as healthy lifestyle and daily supplements of calcium and vitamin D alone seem to be insufficient in holding their bones healthy. Our findings suggest the usefulness of addition of risedronate in order to prevent aromatase inhibitors-related bone loss, not only in case of high-risk of fractures, but also for women at mild-moderate risk. This determines a significant improvement in bone health and a positive impact on HRQoL.