Circulating periostin levels in patients with AS: association with clinical and radiographic variables, inflammatory markers and molecules involved in bone formation

Mechanisms of tissue degeneration mediated by periostin in spinal degenerative diseases and their implications for pathology and diagnosis: a review

Periostin (POSTN) serves a dual role as both a matricellular protein and an extracellular matrix (ECM) protein and is widely expressed in various tissues and cells. As an ECM protein, POSTN binds to integrin receptors, transduces signals to cells, enabling cell activation. POSTN has been linked with various diseases, including atopic dermatitis, asthma, and the progression of multiple cancers. Recently, its association with orthopedic diseases, such as osteoporosis, osteoarthritis resulting from cartilage destruction, degenerative diseases of the intervertebral disks, and ligament degenerative diseases, has also become apparent. Furthermore, POSTN has been shown to be a valuable biomarker for understanding the pathophysiology of orthopedic diseases. In addition to serum POSTN, synovial fluid POSTN in joints has been reported to be useful as a biomarker. Risk factors for spinal degenerative diseases include aging, mechanical stress, trauma, genetic predisposition, obesity, and metabolic syndrome, but the cause of spinal degenerative diseases (SDDs) remains unclear. Studies on the pathophysiological effects of POSTN may significantly contribute toward the diagnosis and treatment of spinal degenerative diseases. Therefore, in this review, we aim to examine the mechanisms of tissue degeneration caused by mechanical and inflammatory stresses in the bones, cartilage, intervertebral disks, and ligaments, which are crucial components of the spine, with a focus on POSTN.

The Role of Sclerostin in Rheumatic Diseases: A Review

Systemic connective tissue disorders constitute a heterogenous group of autoimmune diseases with the potential to affect a range of organs. Rheumatoid arthritis (RA) is a chronic, progressive, autoimmune inflammatory disease affecting the joints. Systemic lupus erythematosus (SLE) may manifest with multiple system involvement as a result of inflammatory response to autoantibodies. Spondyloarthropathies (SpAs) such as ankylosing spondylitis (AS) or psoriatic arthritis (PsA) are diseases characterised by the inflammation of spinal joints, paraspinal tissues, peripheral joints and enthesitis as well as inflammatory changes in many other systems and organs. Physiologically, sclerostin helps to maintain balance in bone tissue metabolism through the Wnt/β-catenin pathway, which represents a major intracellular signalling pathway. This review article aims to present the current knowledge on the role of sclerostin in the Wnt/β-catenin pathway and its correlation with clinical data from RA, SLE, AS and PsA patients.

The Multiple Roles of Periostin in Non-Neoplastic Disease

Periostin, identified as a matricellular protein and an ECM protein, plays a central role in non-neoplastic diseases. Periostin and its variants have been considered to be normally involved in the progression of most non-neoplastic diseases, including brain injury, ocular diseases, chronic rhinosinusitis, allergic rhinitis, dental diseases, atopic dermatitis, scleroderma, eosinophilic esophagitis, asthma, cardiovascular diseases, lung diseases, liver diseases, chronic kidney diseases, inflammatory bowel disease, and osteoarthrosis. Periostin interacts with protein receptors and transduces signals primarily through the PI3K/Akt and FAK two channels as well as other pathways to elicit tissue remodeling, fibrosis, inflammation, wound healing, repair, angiogenesis, tissue regeneration, bone formation, barrier, and vascular calcification. This review comprehensively integrates the multiple roles of periostin and its variants in non-neoplastic diseases, proposes the utility of periostin as a biological biomarker, and provides potential drug-developing strategies for targeting periostin.

Potential Therapeutic Mechanism of Scutellaria baicalensis Georgi against Ankylosing Spondylitis Based on a Comprehensive Pharmacological Model

Background

Scutellaria baicalensis Georgi (SBG) has significant anti-inflammatory and immune-modulating activities and is widely used in the treatment of inflammatory and autoimmune diseases. However, the mechanism of SBG in the treatment of ankylosing spondylitis (AS) remains to be elucidated.

Methods

Differentially expressed genes (DEGs) related to AS were analyzed based on two GEO gene chips. The DEGs were merged with the data derived from OMIM, GeneCards, and PharmGKB databases to ascertain AS-related targets. Active components of SBG and their targets were acquired from the TCMSP database. After overlapping the targets of AS and SBG, the action targets were acquired. Subsequently, protein-protein interaction (PPI) network and core target screening were conducted using the STRING database and Cytoscape software. Moreover, the DAVID platform was used to perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of action targets. Finally, the affinity of major active components and core targets was validated with molecular docking.

Results

A total of 36 active components of SBG were acquired from TCMSP database. Among these, the main active components were baicalein, wogonin, and oroxylin A. The PPI network and screening showed TNF, IL-6, CXCL8, PTGS2, and VEGFA as core targets associated SBG against AS. GO and KEGG analyses indicated that SBG participated in various biological processes, via regulating IL-17, TNF, and NF-κB signaling pathways. Molecular docking results confirmed a strong binding activity between the main active components and the core targets.

Conclusion

The therapeutic mechanism of SBG associated with AS can be characterized as a multicomponent, multitarget, and multipathway mechanism. SBG may be a promising therapeutic candidate for AS.

Serum Pharmacochemistry Combining Network Pharmacology to Discover the Active Constituents and Effect of Xijiao Dihuang Tang Prescription for Treatment of Blood-Heat and Blood-Stasis Syndrome-Related Disease

Xijiao Dihuang Tang (XDT), a classic TCM prescription, has been used to clinically treat blood-heat and blood-stasis syndrome- (BHSS-) related diseases, including hemorrhagic stroke and sepsis. However, the active constituents and mechanism of XDT in the treatment of BHSS-related diseases have not been elucidated due to the lack of appropriate methodologies. In this study, serum pharmacochemistry and network pharmacology were used to explore the active constituents and the mechanism of XDT in the treatment of BHSS-related diseases. The effects of XDT were evaluated using dry yeast-induced rats as rat models with BHSS, which demonstrated the antipyretic and anticoagulant properties of XDT. The HPLC-QTOF/MS/MS assay was used to identify 60 serum constituents of XDT (SCXDT). Then, 338 targets of 60 SCXDT were predicted by integrating multiple databases and the MACCS fingerprint similarity prediction method. The degree of topological properties with targets of 19 key active constituents in SCXDT was identified and evaluated in glutamate-induced PC12 cells. Subsequently, 338 targets of 60 SCXDT were mainly involved in biological processes such as inflammation, coagulation, cell proliferation, and apoptosis, as well as oxidative contingencies via compound-target-disease network analysis. The core targets including IL-1β, IL-6, TNF, NOS3, and MAPK1 were identified using protein-protein interaction network analysis, whereas dozens of signaling pathways such as the p38MAPK signaling pathway were identified using functional pathway enrichment analysis. The results indicated that XDT has broad therapeutic and neuroprotective effects on inflammation, coagulation, oxidative stress, cell proliferation, and apoptosis in dry yeast-induced rats with BHSS and glutamate-induced PC12 cells by regulating the p38MAPK signaling pathway. This study not only discovered the active constituents of XDT but also elaborated its mechanisms in the treatment of BHSS-related diseases by intervening in a series of targets, signaling pathways, and biological processes such as inflammation, coagulation, oxidative stress, neuroprotection. The findings in this study provide a novel strategy for exploring the therapeutic efficacy of TCM prescriptions.

The Role of Sclerostin in Bone Diseases

Sclerostin has been identified as an important regulator of bone homeostasis through inhibition of the canonical Wnt-signaling pathway, and it is involved in the pathogenesis of many different skeletal diseases. Many studies have been published in the last few years regarding sclerostin's origin, regulation, and mechanism of action. The ongoing research emphasizes the potential therapeutic implications of sclerostin in many pathological conditions with or without skeletal involvement. Antisclerostin antibodies have recently been approved for the treatment of osteoporosis, and several animal studies and clinical trials are currently under way to evaluate the effectiveness of antisclerostin antibodies in the treatment of other than osteoporosis skeletal disorders and cancer with promising results. Understanding the exact role of sclerostin may lead to new therapeutic approaches for the treatment of skeletal disorders.

Periostin: An Emerging Molecule With a Potential Role in Spinal Degenerative Diseases

Periostin, an extracellular matrix protein, is widely expressed in a variety of tissues and cells. It has many biological functions and is related to many diseases: for example, it promotes cell proliferation and differentiation in osteoblasts, which are closely related to osteoporosis, and mediates cell senescence and apoptosis in chondrocytes, which are involved in osteoarthritis. Furthermore, it also plays an important role in mediating inflammation and reconstruction during bronchial asthma, as well as in promoting bone development, reconstruction, repair, and strength. Therefore, periostin has been explored as a potential biomarker for various diseases. Recently, periostin has also been found to be expressed in intervertebral disc cells as a component of the intervertebral extracellular matrix, and to play a crucial role in the maintenance and degeneration of intervertebral discs. This article reviews the biological role of periostin in bone marrow-derived mesenchymal stem cells, osteoblasts, osteoclasts, chondrocytes, and annulus fibrosus and nucleus pulposus cells, which are closely related to spinal degenerative diseases. The study of its pathophysiological effects is of great significance for the diagnosis and treatment of spinal degeneration, although additional studies are needed.

Periostin in Allergy and Inflammation

Matricellular proteins are involved in the crosstalk between cells and their environment and thus play an important role in allergic and inflammatory reactions. Periostin, a matricellular protein, has several documented and multi-faceted roles in health and disease. It is differentially expressed, usually upregulated, in allergic conditions, a variety of inflammatory diseases as well as in cancer and contributes to the development and progression of these diseases. Periostin has also been shown to influence tissue remodelling, fibrosis, regeneration and repair. In allergic reactions periostin is involved in type 2 immunity and can be induced by IL-4 and IL-13 in bronchial cells. A variety of different allergic diseases, among them bronchial asthma and atopic dermatitis (AD), have been shown to be connected to periostin expression. Periostin is commonly expressed in fibroblasts and acts on epithelial cells as well as fibroblasts involving integrin and NF-κB signalling. Also direct signalling between periostin and immune cells has been reported. The deposition of periostin in inflamed, often fibrotic, tissues is further fuelling the inflammatory process. There is increasing evidence that periostin is also expressed by epithelial cells in several of the above-mentioned conditions as well as in cancer. Augmented periostin expression has also been associated with chronic inflammation such as in inflammatory bowel disease (IBD). Periostin can be expressed in a variety of different isoforms, whose functions have not been elucidated yet. This review will discuss potential functions of periostin and its different isoforms in allergy and inflammation.

Plasma periostin as a biomarker of osteoporosis in postmenopausal women with type 2 diabetes

INTRODUCTION

Periostin, as an emerging biomarker, is involved in multiple steps in bone metabolism. This study aimed to investigate the correlation between periostin levels and bone mineral density as well as bone turnover markers in postmenopausal women with type 2 diabetes (T2DM).

MATERIALS AND METHODS

This study was a cross-sectional study that included 164 postmenopausal women with T2DM as study subjects and 32 age-matched nondiabetic postmenopausal women with normal bone mineral density (BMD) as healthy control subjects. A total of 164 subjects with T2DM were then divided into three groups according to BMD: the normal BMD group (n = 29), the osteopenia group (n = 70), and the osteoporosis group (n = 65). The clinical data of all subjects along with the relevant biochemical parameter data were collected. Plasma periostin was detected using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Plasma periostin levels were significantly increased in T2DM patients with normal BMD compared with healthy controls (p < 0.05). In the diabetic group, plasma periostin levels were significantly elevated with decreased BMD, were positively correlated with osteocalcin levels (r = 0.162, p = 0.039) and were inversely associated with femoral neck BMD (r = - 0.308, p < 0.001) and total femur BMD (r = - 0.295, p < 0.001). In the case of chronic complications, periostin levels were slightly increased in individuals with complications of diabetic retinopathy, diabetic nephropathy and fracture (p > 0.05).

CONCLUSIONS

The current study demonstrated that plasma periostin levels were significantly associated with BMD in patients with T2DM, and periostin might act as a novel biochemical marker of osteoporosis in postmenopausal women with type 2 diabetes.

The role of biochemical markers of joint tissue remodelling to predict progression and treatment efficacy in inflammatory rheumatic diseases

Structural damage is a hallmark in RA, spondyloarthropy (SpA) and psoriatric arthritis (PsA). Its progression is difficult to predict and current radiological or inflammatory biological markers lack sensitivity. Biochemical markers of bone, cartilage and synovial tissues provide a dynamic indication of the anabolism and catabolism of joint tissues and can be easily measured by immunoassays. Novel biochemical markers including post-translational modifications of matrix proteins and enzyme-generated neoepitopes with increased tissue and/or biological pathway specificity have been developed. Their evaluation in clinical trials of novel biologic therapies and epidemiological studies indicated that their measurements could be useful to predict progression of structural damage and treatment efficacy, independently of current clinical, radiological and biological indices of disease activity. In this paper we briefly describe the latest developments in biochemical markers and critically analyse the clinical data assessing the utility of established and novel biochemical markers in RA, SpA and PsA.

Blockade of periostin-dependent migration and adhesion by curcumol via inhibition of nuclear factor kappa B signaling in hepatic stellate cells

OBJECTIVES

Curcumol, a guaiane-type sesquiterpenoid hemiketal extracted from the herb Rhizoma Curcumae, exhibits multiple-pharmacological activities. We previously reported that curcumol ameliorated hepatic fibrosis by inhibiting hepatic stellate cell (HSC) activation. In this study, we aimed to investigate the effect of curcumol on HSC migration and adhesion, and reveal its regulation mechanisms.

MATERIALS AND METHODS

Cellular viability was determined by Cell Counting Kit-8. Cell migration was detected by boyden chamber and cell scratch experiment. Recombinant human periostin (rh POSTN) and adeno-associated viral (AAV)-GFP-periostin were used to achieve POSTN overexpression in vitro and in vivo, respectively. Nuclear factor kappa B (NF-κB)-p65 overexpression was achieved by using plasmid. ELISA was conducted to detect POSTN level. Immunohistochemistry, qRT-PCR, Western blotting, and immunofluorescence were performed to assess associated factor expression.

RESULTS

Curcumol suppressed HSC migration and adhesion, and reduced the secretion and expression of POSTN. By gain of function POSTN in HSCs, using rh POSTN, we found that the inhibition of HSC migration and adhesion by curcumol depended on the decrease of POSTN. Besides, curcumol protection against chronic CCl₄-caused hepatic fibrosis could be impaired by POSTN overexpression. Moreover, we showed that curcumol repressed NF-κB signaling and the production of pro-inflammatory factor. Importantly, curcumol down-regulation of POSTN was rescued by knock-in of NF-κB, as well as the inhibition of HSC migration and adhesion.

CONCLUSION

These findings reveal the molecular mechanism of curcumol-reduced HSC migration and adhesion, by which points to the possibility of using curcumol based on NF-κB dependent POSTN for the treatment of fibrogenesis.

Tartrate-resistant acid phosphatase 5b, but not periostin, is useful for assessing Paget's disease of bone

BACKGROUND

Periostin is a matricellular protein with a preferential location in cortical bone and periosteal tissue, and tartrate-resistant acid phosphatase 5b (TRAP5b) is a marker of osteoclast numbers. In Paget's disease of bone (PDB), there is increased cortical thickening and probably increased periosteal apposition, along with increased osteoclast numbers.

OBJECTIVES

To analyse if circulating periostin is a biomarker for PDB, and if it is associated with disease activity and involvement of long bones that represent major cortical contribution. Also, to analyse whether TRAP5b, a scarcely explored bone resorption marker, is useful in the assessment of PDB.

PATIENTS AND METHODS

We recruited 42 patients with PDB (13F/29M; 71 ± 11.6 yrs). 71.4% had active disease, 66.6% had polyostotic disease and 54.8% had long bone involvement. Blood and urine samples were taken between 8:00 and 10:00 A.M. after an overnight fast. Periostin and TRAP5b were measured in serum, using commercial ELISA assays (Biomedica and IDS, respectively). Serum total ALP, PINP, CTX, bone ALP and urinary NTX were measured. Reference values for periostin and TRAP5b were obtained from 45 healthy subjects.

RESULTS

Serum periostin did not differ between patients and controls (989.4 ± 173.2 vs. 966.9 ± 195.4 pMol/L, p = 0.572). No significant differences were observed between patients with and without active disease (964.5 ± 168.8 vs.1051.6 ± 175.6 pMol/L, p = 0.143), involvement or not of long bones (1022.2 ± 145.8 vs 949.7 ± 198.2 pMol/L, p = 0.181) and monostotic or polyostotic disease (963.8 ± 198.7 vs 1002.2 ± 161.4 pMol/L, p = 0.505). There were significant correlations between serum periostin and all bone turnover markers (bone ALP, PINP, uNTX, sCTX and TRAP5b) in PDB patients with active disease, but not in the inactive PDB group. Serum TRAP5b was significantly higher in PDB patients than in controls (4.43 ± 1.76 vs. 3.21 ± 1.02 U/L, p < 0.001), in those with active disease (4.98 ± 1.76 vs. 3.07 ± 0.72 U/L, p < 0.001) and in patients with polyostotic disease than in those with monostotic disease (4.81 ± 1.79 vs 3.68 ± 1.5 U/L, p = 0.005). TRAP5b levels were not influenced by previous bisphosphonate treatment (4.14 ± 1.42 vs. 4.84 ± 2.02 U/L, p = 0.206).

CONCLUSIONS

Periostin is not useful for assessing PDB, whilst TRAP5b, which has been a scarcely explored bone turnover marker until now, may be useful in the analysis of this disease, providing new information on the resorption process. In addition, periostin levels correlate with all classical BTMs in active PDB, suggesting that this marker may reflect periosteal and cortical metabolism in accelerated bone turnover states.

Association of Genetic Variants of RANK, RANKL, and OPG with Ankylosing Spondylitis Clinical Features in Taiwanese

Ankylosing spondylitis (AS) is a chronic inflammatory disease that leads to spinal ankylosis. The receptor activator of the nuclear factor-kappa (RANK), RANK ligand, and osteoprotegerin (OPG) (RANK/RANKL/OPG) pathway plays critical roles in bone metabolism and the immune system. The current study was aimed at investigating whether six single-nucleotide polymorphisms (SNPs) within the RANK, RANKL, and OPG genes essential for bone homeostasis are associated with AS. Genotype distributions, allele and haplotype frequencies, were compared between 1120 AS patients and 1435 healthy controls and among AS patients with stratification by syndesmophyte formation, onset age, and HLA-B27 positivity. We found that RANKL SNPs were associated with AS syndesmophyte formation. Notably, the RANKL SNP haplotype rs7984870C/rs9533155G/rs9525641C was negatively associated with AS susceptibility and appeared to protect against syndesmophyte formation in AS. Functionally, RANKL promoter SNPs (rs9525641 C/T and rs9533155 G/C) affected DNA-protein complex formation and promoter activity in promoter reporter analyses. The OPG SNP haplotype rs2073618G/rs3102735T was significantly associated with HLA-B27 negativity in AS patients. Furthermore, AS patients with syndesmophyte formation had significantly lower levels of soluble RANKL levels than those without syndesmophyte formation. Our data suggested a role for RANKL in AS susceptibility and severity.

Longitudinal evaluation of serum periostin levels in patients after large-artery atherosclerotic stroke: A prospective observational study

Increasing evidence supports the involvement of periostin in the pathophysiological processes of stroke and atherosclerosis. The aim of this study was to assess circulating periostin levels at different times after large-artery atherosclerotic (LAA) stroke and their association with stroke. Serum periostin levels were measured using enzyme-linked immunosorbent assay on day 1 in 162 patients with LAA stroke and in 108 age- and sex-matched controls, on day 6 after stroke in 134 patients, and during the 4th week after stroke in 46 of the 162 patients. Stroke severity was determined using the National Institutes of Health Stroke Scale (NIHSS), and the stroke volume was measured. Outcome at 3 months was measured using the modified Rankin Scale (mRS). Our results indicated that periostin levels increased significantly on day 6 after stroke, and this increasing trend persisted for at least 4 weeks after the event. In addition, the increase in periostin levels was positively correlated with the NIHSS scores and stroke volume, but not with the mRS scores after adjusting for the NIHSS scores. In conclusion, these findings suggest that the increase in serum periostin levels observed after stroke may be associated with the stroke severity in patients with LAA stroke.

Association of oxidative stress with clinical characteristics in patients with rheumatoid arthritis

BACKGROUND

Few studies examining the association between oxidative stress and clinical parameters or disease activity in patients with rheumatoid arthritis (RA) are available. Therefore, the objective of this study was to test whether oxidative stress has any association with clinical parameters and disease activity in patients with RA.

MATERIALS AND METHODS

In this post hoc cross-sectional study, 45 patients with RA treated with traditional disease-modifying antirheumatic drugs (DMARDs) ± low-dose glucocorticoids ± nonsteroidal analgesics for at least 3 months were analysed. Oxidative stress parameters were malondialdehyde (MDA), superoxide dismutase (SOD), antioxidant potential (AOP) and nonenzymatic superoxide radical scavenger activity (NSSA). Clinical parameters were pain, patient global assessment, physician global assessment, Health Assessment Questionnaire (HAQ), and disease activity score (DAS28).

RESULTS

Plasma NSSA levels were significantly inversely correlated with tender joints count (r = -.304; P = .042), swollen joints count (r = -.342; P = .021) and DAS28 (r = -.396; P = .009). There were no significant correlations between MDA/SOD/AOP and any of clinical parameters or DAS28 (P > .05 for all). Multiple regression analysis revealed that NSSA was an independent variable of DAS28 (β=-.243, P = .016).

CONCLUSION

The preliminary results demonstrate that plasma NSSA levels were inversely correlated with tender and swollen joints count and DAS28 and that NSSA was independently associated with DAS28, in patients with RA treated with traditional DMARDs; and provide initial support that NSSA may be used as a biomarker of disease activity in patients with RA.

Periostin and sclerostin levels in juvenile Paget's disease

Juvenile Paget's disease (JPD) is a rare, autosomal recessive disorder featuring markedly increased serum alkaline phosphatase activity, indicative of greatly accelerated bone turnover throughout the skeleton. The main aim of this study was to evaluate circulating periostin and sclerostin levels in two adult patients with mild JPD (due to "Balkan" mutation). We measured periostin and sclerostin levels in a previously described woman and a newly diagnosed man with JPD, and 10 apparently healthy individuals, matched (1:5) to JPD patients for gender, age and body mass index. Sclerostin levels were similar between JPD patients and controls. Periostin levels were about 2.5 times higher in JPD patients. Periostin and sclerostin levels were negatively correlated (rs= -0.63; p=0.03). In conclusion, a trend towards higher periostin levels was observed in JPD patients, whereas sclerostin levels were similar to controls.

Evaluation of periostin and factors associated with new bone formation in ankylosing spondylitis: Periostin may be associated with the Wnt pathway

OBJECTIVE

Periostin has been shown to be involved in bone anabolism through the regulation of Wnt-β-catenin signaling. It may be one of the pathogenic mechanisms in syndesmophyte formation in ankylosing spondylitis (AS). The aim of this study was to evaluate serum periostin levels in patients with AS and to assess relationships among biomarkers of bone formation and periostin in disease outcomes, particularly radiographic changes.

METHODS

Ninety-seven consecutive AS patients (78% male) and 48 healthy controls (75% male) were included in the study. Serum periostin, dickkopf-1 (DKK-1), sclerostin and vascular endothelial growth factor (VEGF) levels were measured using commercially available enzyme-linked immunosorbent assay kits. Disease-related characteristics of patients were assessed using Ankylosing spondylitis disease activity score - C-reactive protein (ASDAS-CRP), Bath AS Disease Activity Index, Bath AS Functional Index and Bath AS metrology index. Radiographs were scored using the modified New York criteria and modified Stokes AS spinal score (mSASSS).

RESULTS

Compared with control subjects, patients with AS had significantly lower serum levels of periostin (P < 0.001) and sclerostin (P < 0.001), but higher serum levels of VEGF (P < 0.001) and high-sensitivity CRP (P < 0.001). Serum periostin (P = 0.005) and sclerostin levels (P = 0.016) were significantly lower in patients with very high disease activity according to ASDAS-CRP. Current age (P = 0.009), age at symptom onset (P = 0.021) and hip joint involvement (P = 0.012) were independently associated with the development of syndesmophyte, in contrast to biomarkers of bone metabolism that we evaluated.

CONCLUSION

Our results suggest that periostin is down-regulated in AS patients with highly active disease and may contribute to disease pathogenesis through an interaction with Wnt signaling.

Sclerostin expression and functions beyond the osteocyte

Sclerostin, the product of the SOST gene, is a secreted inhibitor of Wnt signaling that is produced by osteocytes to regulate bone formation. While it is often considered an osteocyte-specific protein, SOST expression has been reported in numerous other cell types, including hypertrophic chondrocytes and cementocytes. Of interest, SOST/sclerostin expression is altered in certain pathogenic conditions, including osteoarthritis and rheumatic joint disease, and it is unclear whether sclerostin plays a protective role or whether sclerostin may mediate disease pathogenesis. Therefore, as anti-sclerostin antibodies are being developed for the treatment of osteoporosis, it is important to understand the functions of sclerostin beyond the regulation of bone formation.

Serum periostin level is not associated with allergic rhinitis or allergic sensitization in Korean children

OBJECTIVES

Periostin is a matricellular protein, synthesized in the airway epithelium and induced by interleukin (IL)-4 and IL-13. The significance of periostin as a biomarker of T helper type 2 cell (Th2)-induced airway inflammation, and as a measure of the response to Th2-targeted therapy, has recently been highlighted. We explored the relationship between serum periostin and allergic rhinitis in Korean children.

METHODS

Data for fifth and sixth grade children from six randomly selected elementary schools located in Jeju and Seogwipo City, Korea, were investigated. Serum periostin levels were determined by enzyme-linked immunosorbent assay. Sex, school grade, body mass index, and presence of allergic nasal symptoms were obtained via a self-reported survey and skin prick testing was performed.

RESULTS

There were no significant differences between groups, when stratification was applied according to sex, grade, presence of atopy, and presence of allergic nasal symptoms. Sex and body mass index were significantly associated with serum periostin levels in multivariate linear regression analysis. However, allergic rhinitis was not associated with serum periostin levels.

CONCLUSION

Allergic rhinitis or allergic sensitization in Korean children did not influence serum periostin levels. Further studies are required to investigate the significance of serum periostin levels in pediatric allergic rhinitis.

Emerging treatment approaches for myeloma-related bone disease

INTRODUCTION

Multiple myeloma is characterized by the presence of osteolytic lesions that leads to devastating skeletal-related events in the majority of patients. Myeloma bone disease is attributed to increased osteoclastic and suppressed osteoblastic activity. Areas covered: Bisphosphonates remain the main treatment option, however they have limitations on their own. Understanding the pathogenesis of myeloma bone disease may provide a roadmap for new therapeutic approaches. The pathway of RANKRANKLOPG pathway has revealed denosumab, a monoclonal antibody targeting RANKL as a novel emerging therapy for myeloma-related bone disease. Furthermore, the Wnt signaling inhibitors dicckopf-1 and sclerostin that are implicated in the pathogenesis of bone destruction of myeloma are now targeted by novel monoclonal antibodies. Activin-A is a TGF-beta superfamily member which increases osteoclast activity and inhibits osteoblast function in myeloma; sotatercept and other molecules targeting activin-A have entered into clinical development. Several other molecules and pathways that play an important role in the pathogenesis of bone destruction in myeloma, such as periostin, adiponectin, Notch and BTK signaling are also targeted in an attempt to develop novel therapies for myeloma-related bone disease. Expert commentary: We summarize the current advances in the biology of myeloma bone disease and the potential therapeutic targets.

High levels of periostin correlate with increased fracture rate, diffuse MRI pattern, abnormal bone remodeling and advanced disease stage in patients with newly diagnosed symptomatic multiple myeloma

Periostin is an extracellular matrix protein that is implicated in the biology of normal bone remodeling and in different cancer cell growth and metastasis. However, there is no information on the role of periostin in multiple myeloma (MM). Thus, we evaluated periostin in six myeloma cell lines in vitro; in the bone marrow plasma and serum of 105 newly diagnosed symptomatic MM (NDMM) patients and in the serum of 23 monoclonal gammopathy of undetermined significance (MGUS), 33 smoldering MM (SMM) patients, 30 patients at the plateau phase post-first-line therapy, 30 patients at first relapse and 30 healthy controls. We found high levels of periostin in the supernatants of myeloma cell lines compared with ovarian cancer cell lines that were not influenced by the incubation with the stromal cell line HS5. In NDMM patients the bone marrow plasma periostin was almost fourfold higher compared with the serum levels of periostin and correlated with the presence of fractures and of diffuse magnetic resonance imaging pattern of marrow infiltration. Serum periostin was elevated in NDMM patients compared with healthy controls, MGUS and SMM patients and correlated with advanced disease stage, high lactate dehydrogenase, increased activin-A, increased bone resorption and reduced bone formation. Patients at first relapse had also elevated periostin compared with healthy controls, MGUS and SMM patients, while even patients at the plateau phase had elevated serum periostin compared with healthy controls. These results support an important role of periostin in the biology of myeloma and reveal periostin as a possible target for the development of antimyeloma drugs.

Alteration of Bone Turnover Markers in Canonical Wingless Pathway in Patients With Ankylosing Spondylitis

Objectives

This study aims to determine the levels of bone turnover markers in canonical wingless pathway in patients with ankylosing spondylitis (AS) and the correlation with disease activity indexes.

Patients and methods

We recruited a total of 43 AS patients (34 males, 8 females; mean age 36.8±9.3 years; range 22 to 62 years) and age- and sex-matched 42 healthy controls (32 males, 10 females; mean age 36.1±9.7; range 24 to 59 years). Serum levels of components of canonical wingless pathway including Dickkopf-1, glycogen synthase kinase-3β, β-catenin, alkaline phosphatase, and osteocalcin were detected using enzyme- linked immunosorbent assay method. All patients were assessed in terms of erythrocyte sedimentation rate, C-reactive protein, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Ankylosing Spondylitis Disease Activity Score, and the modified Stoke's Ankylosing Spondylitis Spine Score. Pearson's correlation test was used to analyze the correlation between serum bone turnover markers and clinical assessment indexes.

Results

No significant difference was observed between AS patients and healthy controls for the levels of glycogen synthase kinase-3β, β-catenin, alkaline phosphatase, and osteocalcin, respectively (p>0.05). The level of Dickkopf-1 was significantly higher in AS patients (1914.5±407.8 pg/mL) than in healthy controls (1729.1±352.9 pg/mL) (p<0.05). There was no correlation between high Dickkopf-1 level and any of the clinical parameters contributing to inflammation or bone formation. However, the correlation between osteocalcin and disease duration was significant in AS patients (r=0.323, p=0.034).

Conclusion

Alteration of bone turnover markers in canonical wingless pathway was observed in AS. This might partially explain the complicated mechanism of bone formation in the disease.

Serum periostin is a potential biomarker for non-alcoholic fatty liver disease: a case-control study

Recent animal studies support close associations of Periostin with hepatosteatosis and steatohepatitis. This study is to evaluate the role of serum periostin in non-alcoholic fatty liver disease (NAFLD). A hospital-based age-/sex-matched case-control study was conducted. Binary logistic regression and receiver operating characteristic (ROC) curve were performed. Serum adipokines were measured by Adipokine Magnetic Bead Panel kits. The serum concentration of Periostin in NAFLD (1914.16 [1323.59-2654.88] ng/ml, P < 0.001) was higher than it in control (1244.94 [837.87-2028.55] ng/ml). The frequency of NAFLD grew (29.8, 52.6, and 67.2%, P < 0.001), as Periostin concentration increased among its tertiles. Compared with the 1st tertile, the 2nd and the 3rd tertiles of Periostin indicated significant associations with higher odds of NAFLD [adjusted odds ratio = 2.602 (95% confidence interval (CI) 1.030-6.575), P = 0.043 and 2.819 (95% CI 1.629-4.878), P < 0.001]. ROC curve of Periostin was developed to predict the presence of NAFLD (area under ROC = 0.693 [95% CI 0.614-0.771], P < 0.001). Lastly, Periostin correlated with several adipokines, including Resistin (r = 0.269, P = 0.018), Adiponectin (r = -0.352, P = 0.002), Interleukin (IL)-6 (r = 0.359, P = 0.001), IL-8 (r = 0.364, P = 0.001), Lipocalin-2 (r = 0.623, P < 0.001), Hepatocyte growth factor (r = 0.522, P < 0.001), and Nerve growth factor (r = 0.239, P = 0.036). It suggests Periostin as a potential biomarker in the management of NAFLD.

Periostin: its role in asthma and its potential as a diagnostic or therapeutic target

Accumulating evidence shows that periostin, a matricellular protein, is involved in many fundamental biological processes such as cell proliferation, cell invasion, and angiogenesis. Changes in periostin expression are commonly detected in various cancers and pre-cancerous conditions, and periostin may be involved in regulating a diverse set of cancer cell activities that contribute to tumorigenesis, cancer progression, and metastasis. Periostin has also been shown to be involved in many aspects of allergic inflammation, such as eosinophil recruitment, airway remodeling, development of a Th2 phenotype, and increased expression of inflammatory mediators. In an in vivo model, bronchoalveolar lavage (BAL) fluid obtained from ovalbumin-challenged mice was found to contain significantly higher levels of periostin compared to BAL samples from control mice. To date, the molecular mechanisms involving periostin in relation to asthma in humans have not been fully elucidated. This review will focus on what is known about periostin and its role in the pathophysiological mechanisms that mediate asthma in order to evaluate the potential for periostin to serve as a biomarker and therapeutic target for the detection and treatment of asthma, respectively.