Dickkopf-related Protein Research Articles

Effects of periodontal and bisphosphonate treatment on the gingival crevicular levels of sclerostin and dickkopf‐1 in postmenopausal osteoporosis with and without periodontitis

Both periodontitis and osteoporosis are associated with osteoclast-related bone resorption. Bone metabolism is regulated by wingless-type MMTV integration site family (WNT), and WNT/β-catenin signals are controlled by physiological antagonists including dickkopf-1 (DKK-1) and sclerostin (SOST). This study examined the effects of periodontal and bisphosphonate (BP) treatment on the gingival crevicular fluid (GCF) sclerostin (SOST) and dickkopf-related protein-1 (DKK-1) levels in osteoporotic and systemically healthy postmenopausal women with and without periodontitis. A total of 48 postmenopausal women were divided into 4 groups (n=12) according to periodontal health and osteoporosis status, as follows: Group OP/P: subjects with both osteoporosis and periodontitis; Group P: systemically healthy subjects with periodontitis; Group OP: periodontally healthy subjects with osteoporosis; Group H: systemically and periodontally healthy controls. Clinical data and GCF SOST and DKK-1 levels of the participants were collected at baseline and at 6 and 12 months following the initiation of periodontal and/or BP treatment in the experimental groups. GCF SOST and DKK-1 data were obtained by ELISA. Clinical improvements were observed in all experimental groups. GCF SOST and DKK1 baseline levels varied significantly between groups due to periodontal disease (p < .001). Following treatment, significant increases in SOST and DKK-1 concentrations and significant decreases in total amounts of SOST were observed in both periodontitis groups (OP/P, P). However, while total amounts of DKK-1 decreased in Group OP/P, in Group P, these amounts had significantly increased at 12 months post-treatment (p < .05). At both 6 and 12 months post-treatment, SOST and DDK1 total amounts in Groups OP/P, OP, and H were similar (p > .05), whereas significant differences were observed between Groups H and P, indicating a deviation from periodontal health in Group P (p < .01). Significant changes in GCF SOST and DKK-1 levels were observed among women with osteoporosis who received both periodontal and BP treatment. A more detailed examination of how these treatment protocols can be combined may lead to new therapeutic approaches towards periodontal disease.

The Impact of Nonsurgical Periodontal Therapy on Serum Levels of Dickkopf-Related Protein-1 in Smokers and Nonsmokers with Periodontitis: A Prospective Comparative Study

PurposeThis study aimed to evaluate and compare Dickkopf-related protein-1 (DKK1) serum levels and periodontal clinical parameters of smokers and nonsmokers with periodontitis at baseline and after nonsurgical periodontal treatment.Patients and MethodsA prospective comparative study was conducted among 24 patients with periodontitis who were divided according to the smoking habits into two groups: nonsmokers (G1) and smokers (G2). All the participants were assessed clinically by recording the probing depth (PD), clinical attachment loss (CAL), plaque index (PI), and bleeding index (BI), and immunologically by measuring the DKK1 serum levels at baseline and six weeks after nonsurgical periodontal therapy.ResultsThe two groups showed a significant decrease in PI, BI, and CAL after periodontal therapy (p < 0.05), while PD was significantly reduced in G1 (p = 0.005). The PI mean value was significantly higher at the baseline in G2 versus G1 (p = 0.050), while PD, BI, and CAL values were not significantly different between the groups (p = 0.056, p = 0.241, and p = 0.381, respectively). For DKK1 serum levels, there was a statistically significant decrease after treatment compared to the baseline for both groups (G1: p < 0.001; G2: p < 0.001) but no significant difference before (p = 0.131) and six weeks after treatment (p = 0.334) between the two groups.ConclusionAlthough nonsurgical periodontal treatment effectively improved periodontal clinical parameters and reduced DKK1 serum levels, there were no significant differences in the DKK1 serum levels among the smokers and nonsmokers with periodontitis.

Roles of DKK3 in cellular adhesion, motility, and invasion through extracellular interaction with TGFBI.

Dickkopf-related protein (DKK) 3, a member of the DKK family, is a secreted glycoprotein that acts as a modulator of Wnt signaling in organogenesis and carcinogenesis. Recent studies have demonstrated that DKK3 has a variety of functions, suggesting that it plays roles not only in tumorigenesis, but also tumor neovascularization, prostatic acinus formation, cardiac vascular remodeling, renal and cardiac fibrosis, and immunological activity. The function of DKK3 is therefore of great interest, but details of the receptors and mechanisms involved have remained unclear. Here, we focused on the extracellular function of DKK3 as a secreted protein, and identified transforming growth factor beta induced protein ig-h3 (TGFBI) as a secreted protein interacting with DKK3. To investigate the function of these secreted proteins, we employed an in vitro cell model involving human hepatocellular carcinoma cells, human embryonic kidney cells, or non-neoplastic hepatocyte cells. We showed that DKK3 functions as an extracellular matrix-like molecule supporting adhesion, motility, and invasion, and that its interaction with TGFBI inhibits the functions of secreted DKK3 in cells expressing both proteins. These results suggest that this extracellular interaction between DKK3 and TGFBI modulates cell adhesion and motility through focal adhesion kinase signaling, and that this might serve as a potential therapeutic target in the context of cancer invasion and metastasis.

Osteotropic proteins in bone marrow do not reflect abundance in bone and bone remodeling in obese females

We assessed the abundance of a wide variety of osteotropic proteins in bone marrow, bone and blood among obese females. Samples were collected from blood, bone marrow and bone. Twenty osteotropic proteins, including bone turnover markers (BTM), cytokines and hormones were measured from 14 obese females. Bland-Altman analysis used to detect systematic or proportional differences between the tissues, and Spearman's correlation to detect differences within the tissues. Eight osteotropic proteins in bone were 2 to 158-fold higher than in bone marrow. BALP in bone marrow was 14-fold higher than in bone. PTH and OC in blood were significantly (p < 0.001) higher than in bone marrow. In bone, vascular endothelial growth factor (VEGF) correlated significantly with several osteotropic proteins. Bone mineral density (BMD) showed a positive correlation with sclerostin (r = 0.87) and dickkopf-related protein 1 (Dkk-1) (r = 0.57) in bone. Our data suggest that this obese female group pronounced differences in osteotropic proteins between bone and bone marrow, limited crosstalk between bone and bone marrow. Furthermore, our data indicate that VEGF is important in regulating bone remodeling in this obese group. • Osteotropic proteins were 2–158 fold higher in bone among obese females. • VEGF is important in the regulation of bone remodeling in this obese group. • BMD showed a significant correlation with sclerostin and Dkk-1 in bone.

Bone Marrow Adiposity, Bone Mineral Density and Wnt/β-catenin Pathway Inhibitors Levels in Hemodialysis Patients

BackgroundMarrow adipose tissue (MAT) is known to accumulate in patients with chronic kidney disease. This pilot study aimed to evaluate bone mineral density (BMD), MAT, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) using computed tomography (CT) scans and to explore correlations between bone parameters, circulating Wnt/β-catenin pathway inhibitor levels, and adipose tissue parameters.MethodsSingle-center cross-sectional pilot study conducted in hemodialysis patients at the Centre Universitaire de Québec, Hôtel-Dieu de Québec hospital, Canada. CT-scan slices were acquired at the levels of the hip, L3 vertebra, and tibia. Volumetric and areal BMD, tibia cortical thickness, VAT and SAT area, and fat marrow index (FMI) were analyzed using the Mindways QCT Pro software. Blood levels of sclerostin, dickkopf-related protein 1 (DKK1), fibroblast growth factor 23, and α-Klotho were assessed. Spearman’s rho test was used to evaluate correlations.ResultsFifteen hemodialysis patients (median age, 75 [66–82] years; 80% male; dialysis vintage, 39.3 [27.4–71.0] months) were included. While inverse correlations were obtained between L3 FMI and BMD, positive correlations were found between proximal tibial FMI and vertebral and tibial BMD, as well as with tibial (proximal and distal) cortical thickness. VAT had a positive correlation with α-Klotho levels, whereas L3 FMI had a negative correlation with DKK1 levels.ConclusionsCT-scan allows simultaneous evaluation of bone and marrow adiposity in dialysis patients. Correlations between MAT and BMD vary depending on the bone site evaluated. DKK1 and α-Klotho levels correlate with adipose tissue accumulation in dialysis patients.

Assessment of Systemic and Maxillary Bone Loss in Cancer Patients with Endo-Periodontal Lesions Using Dkk-1 Biomarker and Dental Radiological Examinations

The aim of our study was to correlate systemic bone loss by evaluating human Dickkopf-related protein 1 (Dkk-1) biomarker compared to horizontal bone loss as well as the presence and size of periapical lesions assessed by dental X-ray (ortopantomography—OPT) and cone beam computed tomography (CBCT) in patients with cancer in the ears, nose and throat (ENT) region vs. healthy controls. The study included 63 subjects divided into a study group of 33 cancer patients with ENT cancer (larynx/oropharynx/sinuses) and a control group of 30 healthy individuals. Blood samples were collected from both groups to assess Dkk-1 level using a sandwich enzyme immunoassay. The dental radiological examination consisted of a panoramic X-ray and a CBCT in order to appraise the horizontal bone loss, the presence and size of the periapical lesions in 2D vs. 3D images. The panoramic X-ray showed that in the control group, the maximum bone loss reached 13.2 mm, with an average of 4.930 ± 3.258 mm, while in the study group, the maximum horizontal bone loss was 11.3 mm, with an average of 5.191 ± 2.109 mm. The CBCT 3D investigation, when compared to the OPT, showed increased values for horizontal bone loss, both in the control group and in the study group; in the control group, the maximum bone loss reached 14.10 mm, with an average of 5.736 ± 3.471 mm, and in the study group, the maximum value was 12.40 mm, and the average was again slightly higher (6.152 ± 2.519 mm). The mean value for Dkk-1 in cancer patients was 1.209 ± 0.110 ng/mL, significantly lower than the value observed in healthy patients (1.712 ± 0.100 ng/mL). CBCT revealed higher values for the investigated parameters when compared to panoramic X-rays. Taking into account the preliminary nature of our study, we observed a significant correlation between the level of bone loss recorded by the Dkk-1 biomarker and radiological dental examination in patients with ENT cancer when compared to the control group.

Circ_0000284 Promoted Acute Pancreatitis Progression through the Regulation of miR-10a-5p/Wnt/β-Catenin Pathway.

Circular RNAs (circRNAs) have been found to be involved in the progression of acute pancreatitis (AP). The objective of our study was to investigate the effects of circ_0000284 on caerulein-induced AR42J cell injury. To mimic AP in vitro, rat pancreatic acinar AR42J cells were treated with caerulein. The expression of circ_0000284 and miR-10a-5p was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Enzyme-linked immunosorbent assay (ELISA) was employed to determine the content of inflammatory cytokines interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor α (TNF-α). Western blotting was applied to analyze the levels of Wnt/β-catenin pathway-related and apoptosis-related proteins. Cell viability and apoptosis were monitored by Counting Kit-8 (CCK-8) assay and flow cytometry, respectively. The target connection between circ_0000284 and miR-10a-5p was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. AP induced inflammation in patients, and caerulein treatment increased apoptosis and inflammation in AR42J cells. Circ_0000284 was upregulated in serum of AP patients and caerulein-induced AR42J cells, while Wnt/β-catenin pathway was inactivated. Knockdown of circ_0000284 could decrease apoptosis and inflammation in caerulein-induced AR42J cells, which was attenuated by miR-10a-5p inhibition or Wnt signaling pathway antagonist Dickkopf-related protein 1 (DKK1). MiR-10a-5p was sponged by circ_000028 and was downregulated in caerulein-induced AR42J cells. Circ_0000284 depletion could protect caerulein-induced AR42J cells from apoptosis and inflammation by upregulating miR-10a-5p expression and activating Wnt/β-catenin pathway, underscoring a potential target for AP therapy.

Actions of CSF2 and DKK1 on bovine embryo development and pregnancy outcomes are affected by composition of embryo culture medium

Procedures for in vitro embryo production in cattle have not been optimized. In the current experiment, we utilized a 3 × 3 factorial design to test whether the proportion of embryos becoming blastocysts in culture and the pregnancy rate after embryo transfer are affected by type of serum in the medium [no serum; 3% (v/v) KnockOut Serum Replacement (SR); 3% (v/v) fetal bovine serum (FBS)] and addition of specific embryokines [vehicle; 10 ng/mL colony stimulating factor 2 (CSF2); 100 ng/mL dickkopf related protein 1 (DKK1)] at day 5 of culture. Embryos were produced using abattoir-derived ovaries and Y-sorted semen from two Angus sires. The percent of putative zygotes and cleaved embryos becoming blastocysts was improved by SR and FBS. Pregnancy rate at day 30 was determined for 1426 Nelore recipients and calving rate for 266 recipients. In the absence of CSF2 or DKK1, pregnancy rates were lower for embryos cultured with SR or FBS. CSF2 and DKK1 reduced pregnancy rate for embryos cultured without serum but had no detrimental effect in the SR or FBS groups. Indeed, CSF2 blocked the negative effect of FBS on pregnancy rate. Data on birth weights were available for 67 bull calves. There were no effects of treatment. The sire used to produce embryos had significant and large effects on development to the blastocyst stage, pregnancy rate at day 30, calving rate and pregnancy loss between day 30 and calving. Results indicate that (1) SR and FBS can improve embryonic development in vitro while also compromising competence of embryos to survive after transfer, (2) actions of CSF2 and DKK1 depend upon other characteristics of the embryo production system, and (3) sire can have a large effect on embryonic development before and after transfer.

MO947: Evaluation of Bone Metabolism Markers in Kidney Transplant Recipients

Abstract BACKGROUND AND AIMS Immunosuppressive therapies, pre-existing renal osteodystrophy, de novo hyperparathyroidism, and other traditional risk factors influence Mineral and Bone Disorder (MBD) after kidney transplantation. However, little is known about their effect on bone metabolism biomarkers. Therefore, we aimed to understand how kidney transplant affects bone metabolism markers in comparison to patients on hemodialysis and healthy individuals. METHOD This is a cross-sectional study with 57 kidney transplant patients, 36 patients on hemodialysis, and 31 healthy controls. Plasma concentrations of Dickkopf-related protein 1 (DKK1), osteoprotegerin (OPG), osteocalcin (OC), osteopontin (OPN), sclerostin (SOST) and fibroblast growth factor 23 (FGF-23) were measured using the Luminex-based microbead assay (HBNMAG-51K, Millipore, Billerica, MA) in these three groups. Associations between the measurements of these molecules with clinical, demographic, and laboratory data were evaluated. For variables without Gaussian distribution, Mann–Whitney test was used to compare two groups and the Kruskal–Wallis test for comparisons between more than two groups. For variables with normal distribution, comparisons between two groups were made by unpaired Student's t-test and for more than two groups by analysis of variance followed by Bartlett’s post-test. Pearson or Spearman tests were adopted to evaluate correlations according to the variables’ distribution. All statistical tests were two-tailed with a significance level of P &amp;lt; 0.05. RESULTS Transplant recipients had significantly lower levels of DKK1 (P &amp;lt; 0.001), OPG (P &amp;lt; 0.001), OC (P &amp;lt; 0.001), OPN (P = 0.001), OST (P &amp;lt; 0.001) and FGF-23 (P &amp;lt; 0.001) when compared with patients on hemodialysis. In comparison to healthy controls, transplant recipients also presented lower levels of DKK1 (P = 0.019), OPG (P &amp;lt; 0.001), OC (P = 0.027), SOST (P &amp;lt; 0.001) and FGF-23 (P = 0.043) (Figure 1). Regarding demographic data, women presented lower plasma SOST levels when compared with men in the hemodialysis group (P = 0.012). Different correlations between the human bone metabolism components were detected in transplant recipients and hemodialysis patients. In the transplant group, DKK1 was positively correlated with SOST (r = 0.484, P = 0.001), OPN (r = 0.420, P = 0.005) and OPG (r = 0.521, P &amp;lt; 0.001). In the same group, SOST levels were positively correlated with FGF-23 (r = 0.424, P = 0.027, Figure 2D) and OPG (r = 0.703, P &amp;lt; 0.001), while OC only positively correlated with OPN (r = 0.572, P &amp;lt; 0.001). By contrast, patients on hemodialysis only showed positive correlations between OPN and DKK1 (r = 0.420, P = 0.005) and between SOST and OPG (r = 0.757, P &amp;lt; 0.001). Concerning laboratory parameters and their correlations with human bone metabolism molecules, both transplant recipients and hemodialysis patients showed a negative correlation between 25(OH)vitamin D levels and FGF-23. On the other hand, ALP levels were positively correlated with different molecules in the two groups. In transplant patients, ALP levels positively correlated with OPN (r = 0.572, P &amp;lt; 0.001), while, in hemodialysis patients, the positive correlation was with OPG (r = 0.548, P = 0.012). CONCLUSION Our findings showed a reduction in bone metabolism markers, DKK1, OPG, OC, OPN and SOST after kidney transplantation. The first years after kidney transplantation modulate MBD markers, revealing a significant improvement of MBD associated with end-stage kidney disease.

Anticonvulsive and Neuroprotective Effects of Eupafolin in Rats Are Associated with the Inhibition of Glutamate Overexcitation and Upregulation of the Wnt/β-Catenin Signaling Pathway.

Several plant compounds have been found to possess neuroactive properties. The aim of this study was to investigate the anticonvulsant effect of eupafolin, a major active component extracted from Salvia plebeia, a herb used in traditional medicine for its anti-inflammatory properties. To this end, we assessed the anticonvulsant effects of eupafolin in rats intraperitoneally (i.p.) injected with kainic acid (KA) to elucidate this mechanism. Treatment with eupafolin (i.p.) for 30 min before KA administration significantly reduced behavioral and electrographic seizures induced by KA, similar to carbamazepine (i.p.), a widely used antiepileptic drug. Eupafolin treatment also significantly decreased KA seizure-induced neuronal cell death and glutamate elevation in the hippocampus. In addition, eupafolin notably reversed KA seizure-induced alterations in α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit GluR2, glutamate decarboxylase 67 (GAD67, GABAergic enzyme), and Wnt signaling-related proteins, including porcupine, Wnt1, phosphorylated-glycogen synthase kinase-3β, β-catenin, and Bcl-2 in the hippocampus. Furthermore, the increased level of Dickkopf-related protein 1 (Dkk-1, a Wnt signaling antagonist) and the decreased level of Disheveled1 (Dvl-1, a Wnt signaling activator) in the hippocampus of KA-treated rats were reversed by eupafolin. This study provides evidence of the anticonvulsant and neuroprotective properties of eupafolin and of the involvement of regulation of glutamate overexcitation and Wnt signaling in the mechanisms of these properties. These findings support the benefits of eupafolin in treating epilepsy.

Effects of Biological/Targeted Therapies on Bone Mineral Density in Inflammatory Arthritis.

Inflammatory arthritis has been reported to be associated with the development of osteoporosis. Recent research has investigated the mechanisms of bone metabolism in chronic inflammatory arthritis such as rheumatoid arthritis (RA) and spondyloarthritis (SpA). Progress in both animal and clinical studies has provided a better understanding of the osteoclastogenesis-related pathways regarding the receptor activator of nuclear factor-κB ligand (RANKL), anti-citrullinated protein antibodies (ACPAs), and Wnt signaling and Dickkopf-related protein 1 (Dkk-1). The complex interplay between inflammatory cytokines and bone destruction has been elucidated, especially that in the interleukin-17/23 (IL-17/23) axis and Janus kinase and signal transducer and activator of transcription (JAK-STAT) signaling. Moreover, advances in biological and targeted therapies have achieved essential modifications to the bone metabolism of these inflammatory arthritis types. In this narrative review, we discuss recent findings on the pathogenic effects on bone in RA and SpA. Proinflammatory cytokines, autoantibodies, and multiple signaling pathways play an essential role in bone destruction in RA and SpA patients. We also reviewed the underlying pathomechanisms of bone structure in biological and targeted therapies of RA and SpA. The clinical implications of tumor necrosis factor inhibitors, abatacept, rituximab, tocilizumab, Janus kinase inhibitors, and inhibitors of the IL-17/23 axis are discussed. Since these novel therapeutics provide new options for disease improvement and symptom control in patients with RA and SpA, further rigorous evidence is warranted to provide a clinical reference for physicians and patients.

Androgen/Wnt/β-catenin signal axis augments cell proliferation of the mouse erectile tissue, corpus cavernosum.

The murine penile erectile tissues including corpus cavernosum (CC) are composed of blood vessels, smooth muscle, and connective tissue, showing marked sexual differences. It has been known that the androgens are required for sexually dimorphic organogenesis. It is however unknown about the features of androgen signaling during mouse CC development. It is also unclear how androgen-driven downstream factors are involved such processes. In the current study, we analyzed the onset of sexually dimorphic CC formation based on histological analyses, the dynamics of androgen receptor (AR) expression, and regulation of cell proliferation. Of note, we identified Dickkopf-related protein 2 (Dkk2), an inhibitor of β-catenin signaling, was predominantly expressed in female CC compared with male. Furthermore, administration of androgens resulted in activation of β-catenin signaling. We have found the Sox9 gene, one of the essential markers for chondrocyte, was specifically expressed in the developing CC. Hence, we utilized CC-specific, Sox9 CreERT2 , β-catenin conditional mutant mice. Such mutant mice showed defective cell proliferation. Furthermore, introduction of activated form of β-catenin mutation (gain of function mutation for Wnt/β-catenin signaling) in CC induced augmented cell proliferation. Altogether, we revealed androgen-Wnt/β-catenin signal dependent cell proliferation was essential for sexually dimorphic CC formation. These findings open new avenues for understanding developmental mechanisms of androgen-dependent cell proliferation during sexual differentiation.

Dickkopf‑3 and β‑catenin play opposite roles in the Wnt/β‑catenin pathway during the abnormal subchondral bone formation of human knee osteoarthritis.

Osteoarthritis (OA) is condition which poses a main concern to the aging population and its severity is expected to increase with the increasing life expectancy. In the future, several possible targets for OA treatment need to be defined. Dickkopf-related protein 3 (DKK3) is an atypical member of the Wnt-antagonistic dickkopf-related protein (DKK) family. The availability of research into the role of DKK3 in the abnormal remodeling of subchondral bone in human knee joints is currently limited. Thus, the aim of the present study was the evaluation of DKK3 expression in the abnormal bone remodeling of subchondral bone in human knee OA in order to clarify the role of DKK3 in subchondral bone remodeling and to acknowledge its potential relevance to β-catenin. In total, 38 specimens were collected from osteotomies of the medial tibial plateau of the human knee. The patient samples were then divided into the normal, mild, moderate and severe symptom groups, according to the Osteoarthritis Research Society International (OARSI) score. Following hematoxylin and eosin (H&E) and Safranin O-fast green staining for alkaline phosphatase (AZO method), changes in the distribution and number of osteocytes in the subchondral bone and the degree of sclerosis of the subchondral bone were observed. Immunohistochemical staining, immunofluorescence, western blot analysis and reverse-transcription quantitative PCR (RT-qPCR) were used for the detection of DKK3 and β-catenin expression level changes in osteoblasts in the subchondral bone of the medial tibial plateau. H&E and alkaline phosphatase staining revealed that the total number of osteocytes in the subchondral bone increased with the severity of the disease. The samples were also evaluated using Safranin O-Fast Green staining and were attributed a score according to the OARSI scoring system: The scoring number and cartilage damage increased along with OA severity. Immunohistochemistry and immunofluorescence assays demonstrated that β-catenin expression in osteocytes increased from mild to moderate, whereas DKK3 expression decreased with the development of arthritis from normal, mild to moderate. According to the results of western blot analysis, β-catenin expression was higher in moderate OA and then decreased in severe OA. On the other hand, the DKK3 levels decreased along with the progression from normal, mild to moderate OA. The results of RT-qPCR demonstrated that β-catenin and DKK3 gene expression differed with the degree of OA. On the whole, the present study demonstrates that DKK3 and β-catenin may play opposite roles in OA subchondral bone remodeling.

Decreased Serum Wnt Antagonist Levels in Patients With Active Acromegaly

ObjectiveThe Wnt signaling pathway is an important modulator of bone metabolism. This study aims to clarify the changes in Wnt antagonists in active and biochemically controlled acromegalic patients. MethodsWe recruited 77 patients recently diagnosed with acromegaly. Of those, 41 patients with complete follow-up data were included. Thirty healthy patients matched for age, sex, and body mass index served as controls. At baseline and posttreatment, Wnt antagonists (sclerostin [SOST], dickkopf-related protein 1 [DKK-1], and Wnt inhibitory factor 1 [WIF-1]), bone turnover markers (osteocalcin, procollagen type 1 N-terminal propeptide [P1NP], and C-terminal telopeptide of type 1 collagen [CTX]) and the bone remodeling index were investigated. ResultsAcromegalic patients had higher serum osteocalcin, P1NP, and CTX and a higher bone remodeling index than controls (P < .01). Serum SOST, DKK-1, and WIF-1 levels were significantly decreased in patients compared to controls (all P < .01). Serum SOST and WIF-1 levels were negatively correlated with growth hormone levels; SOST levels were positively correlated with WIF-1. After treatment, serum bone turnover markers and the bone remodeling index decreased, while SOST and WIF-1 significantly increased (P < .05). DKK-1 levels did not change compared to baseline (P > .05). In biochemically controlled patients, SOST and WIF-1 levels and bone turnover markers were restored and did not differ from those of the control participants (all P > .05). ConclusionPatients with active acromegaly exhibited significantly decreased Wnt antagonist levels. The reduction in Wnt antagonists is a compensatory mechanism to counteract increased bone fragility in active acromegaly.

Calcitriol and enamel matrix derivative differentially regulated cemento-induction and mineralization in human periodontal ligament-derived cells.

Alveolar bone and cementum share many biological and developmental similarities. The mineralizing effect of calcitriol has been previously reported. Yet, its cemento-inductivity has not been confirmed. This study evaluated the potential cemento-inductivity effect of calcitriol and enamel matrix derivative (EMD) on human periodontal ligament-derived cells (hPDLCs). The hPDLCs obtained from extracted third molars or premolars were cultured with calcitriol, or EMD. Cementogenic gene expression was examined using real-time quantitative reverse transcription polymerase chain reaction. Expression analysis also included cementoblast-specific markers, cementum protein 1 (CEMP1), cementum attachment protein (CAP), and recently reported cementoblast-enriched genes, secreted frizzled related protein 1 (SFRP1), and Dickkopf-related protein 1 (DKK1). Mineralization capacities were evaluated by alkaline phosphatase (ALP) activity, Alizarin Red, and Von Kossa staining followed by scanning electron microscope imaging and element mapping. Among tested conditions, 10nM calcitriol enhanced most cementogenic gene expression, transforming growth factor-β1, bone morphogenetic proteins (BMP-2 and BMP-4), core-binding factor subunit alpha-1/Runt-related transcription factor 2, Type I collagen, ALP, bone sialoprotein, osteopontin), osteocalcin, CEMP1, and CAP, and Wnt signaling negative modulators, SFRP1 and DKK1, along with highest ALP activity and mineralization formation in hPDLCs. However, only moderate CEMP1 protein was observed. In contrast, EMD stimulated stronger CEMP1 and CAP protein, but presented weaker mineralization capacity, hinting at the possibility that strong stimulation of mineralization might dominate cemetogenic specific factors and vice versa. Calcitriol demonstrated not only great osteoinductivity, but also the potential to induce cementogenic gene expression by initiating hPDLC differentiation and promoting mineralization. Compared with calcitriol, EMD promoted cemento-inductivity in hPDLCs at a later time point via highly expressed CEMP1 and CAP protein, but with less mineralization. Thus, calcitriol and EMD could provide differential enhancement of cemento-induction and mineralization, likely acting at various differentiation stages.

Could Bone Biomarkers Predict Bone Turnover after Kidney Transplantation?—A Proof-of-Concept Study

Aim: Bone disease after kidney transplant (KT) results from multiple factors, including previous bone and mineral metabolism disturbances and effects of transplant-related medications. New biomolecules have been recently associated with the development and progression of the chronic kidney disease–associated bone and mineral disorder (CKD-MBD). These include sclerostin and the soluble receptor activator of nuclear factor-kB ligand (sRANKL). Methods: To better understand the role of biomarkers in post-transplant bone disease, this study was designed to prospectively evaluate and correlate results from the histomorphometric analysis of bone biopsies after KT with emerging serum biomarkers of the CKD-MBD: sclerostin, Dickkopf-related protein 1 (Dkk-1), sRANKL and osteo-protegerin (OPG). Results: Our data shows a significant increase in plasma levels of bioactive sclerostin after KT accompanied by a significant reduction in plasma levels of Dkk-1, suggesting a promotion of the inhibition of bone formation by osteoblasts through the activation of these inhibitors of the Wnt signaling pathway. In addition, we found a significant increase in plasma levels of free sRANKL after KT accompanied by a significant reduction in plasma levels of its decoy receptor OPG, suggesting an enhanced bone resorption by osteoclasts mediated by this mechanism. Conclusions: Taken together, these results suggest that the loss of bone volume observed after KT could be explain mainly by the inhibition of bone formation mediated by sclerostin accompanied by an enhanced bone resorption mediated by sRANKL.

IL-36γ promotes psoriasis-like features in keratinocytes in an imiquimod-induced murine model of psoriasis

IntroductionPsoriasis is a recurrent, chronic inflammatory skin disease with complex pathogenesis. The disease imposes a heavy burden on patients. Interleukin (IL)-36γ belongs to the IL-36 family and is predominantly expressed by epithelial cells. IL-36γ is upregulated in psoriasis lesions. However, the effects of IL-36γ in keratinocytes remain unclear.Material and methodsEighteen IL-36γ-deficient mice were divided into three groups: the vaseline group, the imiquimod (IMQ) group, and the IMQ/IL-36γ group. Vaseline or IMQ was administered for 6 consecutive days. The severity of psoriasis-like lesions was evaluated using a modified Psoriasis Area and Severity Index (PASI) scoring system. Production of cytokines and expression of differentiation markers were assessed by immunohistochemistry.ResultsIMQ-induced psoriasis lesions were significantly more severe in IMQ/IL-36γ-treated mice compared with vaseline-treated and IMQ-treated mice, as shown by an exacerbated inflammatory phenotype, increased numbers of blood vessels, increased infiltration of cells, and increased epidermal thickness. Expression of loricrin and keratin 5 in skin lesions was decreased following treatment with IL-36γ. Levels of IL-17A, interferon-γ, β-catenin and Dickkopf-related protein 1 were elevated in keratinocytes within psoriatic lesions following IL-36γ stimulation.ConclusionsTogether, these data showed that IL-36γ contribute to abnormal keratinocytes proliferation and keratinocyte-related proinflammatory cytokines, and suggest that IL-36γ may play an important role in the pathogenesis of psoriasis.

Serum HMGB1, DKK1, and ACE2 as a Function of Lung Injuries in COVID-19 Patients

There is a need for a biomarker for lung injury in COVID-19 patients. In the present study, an attempt was carried out to examine the role of Dickkopf-related protein 1 (DKK1), High-mobility group box 1 protein (HMGB1), angiotensin-converting enzyme 2 (ACE2) as a function for the lung abnormalities in CT-scan (LACTS). To perform the goals, DKK1, HMGB1, and ACE2 were measured in patients and controls using the ELISA technique. In contrast, other parameters were measured spectrophotometrically. The results showed decreased SpO2 and albumin and an increase in the serum biochemical parameters (glucose, urea, creatinine, D-dimer, ACE2, DKK1, and HMGB1) in COVID-19 patients compared with the control group. In COVID-19 patients, the percentages of the lung abnormalities in CT-scan% are 40.67±11.84. The results showed that those patients with LACTS patients are slightly older and have lower SpO2 than the patients without the LACTS group. ACE2 shows a significant correlation with SpO2 (ρ = 0.336, p&lt;0.01) and a negative correlation with albumin (ρ = -0.197, p&lt;0.05). Other parameters showed no significant correlation with the measured biomarkers. In conclusion, COVID-19 patients have higher ACE, DKK1, and HMGB1 indicating the involvement of the pathways of these biomarkers in the disease progression including lung injury.

Ginger extract suppresses the activations of NF-κB and Wnt pathways and protects inflammatory arthritis.

Rheumatoid arthritis (RA) is a disabling inflammatory disorder. Ginger is used for food and medicine to treat arthralgia, sprains, and muscle aches. Anti-inflammatory effects of ginger have been observed. The aim of our study was to detect the effects of ginger on experimentally induced inflammatory arthritis. Female Wistar albino rats (n = 21) were randomly separated into three groups (control, arthritis, and arthritis + ginger). Arthritis was generated by an appropriate method using type 2 collagen and Freund's adjuvant (collagen-induced arthritis model). The ginger group was treated starting at the first collagen injection with ginger root extract for 32 days by oral gavage (50 mg/kg/daily). Interleukin (IL)-6, IL-17, tumor necrosis factor-α (TNF-α), sclerostin, dickkopf-related protein-1 (DKK-1), and obestatin serum levels were studied by enzyme-linked immunosorbent assay method. Tissue TNF-α, IL-17, cyclooxygenase-2 (COX-2), and nuclear factor kappa B (NF-κB) levels were detected using the Western blot method. Mean arthritis score and serum levels of TNF-α, IL-6, and IL-17 were significantly decreased in ginger group than in the arthritis group. Increased sclerostin serum level and decreased DKK-1 serum levels were detected in ginger group compared with arthritis group. The decreases of IL-17, TNF-α, COX-2, and NF-κB tissue levels were statistically significant in the ginger group compared with arthritis group. Histopathological evaluation of the ginger group showed a decrease in the inflammation score compared to arthritis group. It can be concluded that ginger has protective properties in the development of inflammatory arthritis. The antiarthritic acts of ginger are related to NF-κB activity and Wnt pathway. Thus, it may be suggested that ginger is a candidate to research in human RA treatment.

Total NT-proBNP, a novel biomarker related to recurrent atrial fibrillation

BackgroundNovel circulating biomarkers may help in understanding the underlying mechanisms of atrial fibrillation (AF), a challenge for AF management and prevention of cardiovascular (CV) events. Whether glycosylation affects the prognostic value of N-terminal pro-B type natriuretic peptide (NT-proBNP) in AF is still unknown.ObjectivesTo test how deglycosylated total NT-proBNP, NT-proBNP and a panel of biomarkers are associated with: (1) recurrent AF, (2) first hospitalization for CV reasons.MethodsA total of 382 patients of the GISSI-AF trial in sinus rhythm with a history of AF, echocardiographic variables, total NT-proBNP, NT-proBNP and nine additional biomarkers [Total N-terminal pro-B type natriuretic peptide (Total NT proBNP), N-terminal pro-B type natriuretic peptide (NTproBNP), Angiopoietin 2 (Ang2), Bone morphogenic protein-10 (BMP10), Dickkopf-related protein-3 (DKK3), Endothelial cell specific molecule-1 (ESM1), Fatty acid-binding protein 3 (FABP3), Fibroblast growth factor 23 (FGF23), Growth differentiation factor-15 (GDF15), Insulin-like growth factor-binding protein-7 (IGFBP7) and Myosin binding protein C3 (MYPBC3)]. were assayed at baseline, 6 and 12 months under blind conditions in a laboratory at Roche Diagnostics, Penzberg, Germany. The associations between circulating biomarkers and AF at the 6- and 12-month visits, and their predictive value, were assessed in multivariable models with logistic regression analysis and Cox proportional hazards regression analysis. Biomarkers associations were modelled for 1SD increase in their level.ResultsOver a median follow-up of 365 days, 203/382 patients (53.1%) had at least one recurrence of AF and 16.3% were hospitalized for CV reasons. Total NT-proBNP, NT-proBNP, Ang2 and BMP10 showed the strongest associations with ongoing AF. Natriuretic peptides also predicted recurrent AF (total NT-proBNP: HR:1.19[1.04–1.36], p = 0.026; NT-proBNP: HR:1.19[1.06–1.35], p = 0.016; Ang2: HR:1.07[0.95–1.20], p = 0.283; BMP10: HR:1.09[0.96–1.25], p = 0.249) and CV hospitalization (total NT-proBNP: HR:1.57[1.29–1.90], p < 0.001 1.63], p = 0.097).ConclusionsThe association of total NT-proBNP with the risk of AF first recurrence was similar to that of NT-proBNP, suggesting no influence of glycosylation. Analogous results were obtained for the risk of first hospitalization for CV reasons. Natriuretic peptides, Ang2 and BMP10 were associated with ongoing AF. Findings from the last two biomarkers point to a pathogenic role of cardiac extracellular matrix and cardiomyocyte growth in the myocardium of the right atrium and ventricle.