Role of Periostin in Cardiac Valve Development

Gene expression of Postn and FGF7 in canine chordae tendineae and their effects on flexor tenocyte biology

Chordae tendineae, referred to as heart tendinous cords, act as tendons connecting the papillary muscles to the valves in the heart. Their role is analogous to tendons in the musculoskeletal system. Despite being exposed to millions of cyclic tensile stretches over a human's lifetime, chordae tendineae rarely suffer from overuse injuries. On the other hand, musculoskeletal tendinopathy is very common and remains challenging in clinical treatment. The objective of this study was to investigate the mechanism behind the remarkable durability and resistance to overuse injuries of chordae tendineae, as well as to explore their effects on flexor tenocyte biology. The messenger RNA expression profiles of chordae tendineae were analyzed using RNA sequencing and verified by quantitative reverse transcription polymerase chain reaction  and immunohistochemistry. Interestingly, we found that periostin (Postn) and fibroblast growth factor 7 (FGF7) were expressed at significantly higher levels in chordae tendineae, compared to flexor tendons. We further treated flexor tenocytes in vitro with periostin and FGF7 to examine their effects on the proliferation, migration, apoptosis, and tendon-related gene expression of flexor tenocytes. The results displayed enhanced cell proliferation ability at an early stage and an antiapoptotic effect on tenocytes, while treated with periostin and/or FGF7 proteins. Furthermore, there was a trend of promoted tenocyte migration capability. These findings indicated that Postn and FGF7 may represent novel cytokines to target flexor tendon healing. Clinical significance: The preliminary discovery leads to a novel idea for treating tendinopathy in the musculoskeletal system using specific molecules identified from chordae tendineae.

The comprehensive study on the role of POSTN in fetal congenital heart disease and clinical applications

BACKGROUND

Congenital heart defect (CHD) is the most common congenital abnormality, and it has long been a clinical and public health concern. Our previous findings have found Periostin (POSTN) and Pappalysin-1 (PAPPA) as potential biomarkers for fetal CHD. We aim to further elucidate POSTN's role in fetal heart development and explore the clinical applicability of POSTN and PAPPA as diagnostic marker for fetal CHD. This study is poised to establish a theoretical framework for mitigating the incidence of CHD and advance a novel approach for prenatal screening of fetal CHD.

METHODS

We verified differential expression of POSTN and PAPPA in gravida serum and fetal amniotic fluid based on our previous research. We established the Postn knockout mouse by CRISPR/Cas9 to investigate whether Postn deletion leads to cardiac abnormalities in mice. Besides, we explored the mechanism of POSTN on heart development through Postn knockout mouse model and cell experiments. Finally, we established the logistic regression model and decision curve analysis to evaluate the clinical utility of POSTN and PAPPA in fetal CHD.

RESULTS

We observed a significant decrease in POSTN and increase in PAPPA in the CHD group. Atrial septal defects occurred in Postn-/- and Postn± C57BL/6 fetal heart, while ventricular septal defects with aortic saddle were observed in Postn± C57BL/6 fetal heart. Disruption of the extracellular matrix (ECM) in cardiomyocytes and multiple abnormalities in cellular sub-organelles were observed in Postn knockout mice. POSTN may positively regulate cell behaviors and unsettle ECM via the TGFβ-Smad2/3 signaling pathway. The combination of serum biomarkers POSTN and PAPPA with Echocardiogram can enhance the diagnostic accuracy of CHD. Furthermore, the comprehensive model including POSTN, PAPPA, and two clinical indicators (NT and age) exhibits significantly higher predictive ability than the diagnosis group without the use of serum biomarkers or clinical indicators.

CONCLUSIONS

It is the first evidence that Postn deletion leads to cardiac developmental abnormalities in fetal mice. This may involve the regulation of the TGFβ signaling pathway. Importantly, POSTN and PAPPA possess clinical utility as noninvasive prenatal promising screening indicators of CHD.

Identification of Gravida Serum Biomarkers for Noninvasive Prenatal Diagnosis Fetal Congenital Heart Disease

Congenital heart disease (CHD) is well established as the most common congenital defect worldwide. Given the lack of biomarkers available, we aimed to identify new biomarkers for the noninvasive prenatal diagnosis of fetal CHD. This study used data-independent acquisition (DIA) to explore potential protein biomarkers that co-expressed in gravida serum (GS) and fetal amniotic fluid (AF). Next, parallel reaction monitoring (PRM), enzyme-linked immunosorbent assay (ELISA), receiver operating characteristic curve (ROC) analysis, and the immunohistochemistry (IHC) were performed to validate the potential biomarkers. Based on DIA and PRM proteomics and bioinformatics results, we identified POSTN and PAPPA in GS as candidate biomarkers. Their differential expression during ELISA and IHC were generally consistent with our proteomics results. POSTN combined with PAPPA in GS yield a good diagnose fetal CHD with sensitivity of 83.9%, specificity of 73.9%, and an area under curve (AUC) of 0.842. This is the first study showing that POSTN in GS and AF is associated with fetal CHD. POSTN and PAPPA have huge prospects for application as potential biomarkers in the noninvasive prenatal diagnosis of fetal CHD. Congenital heart disease (CHD) is well-established as the most common congenital defect worldwide. Given the lack of biomarkers available, we aimed to identify new biomarkers for the noninvasive prenatal diagnosis of fetal CHD. We used data independent acquisition (DIA) to explore potential protein biomarkers that co-expressed in gravida serum (GS) and fetal amniotic fluid (AF). Next, parallel reaction monitoring (PRM), enzyme-linked immunosorbent assay (ELISA), receiver operating characteristic curve (ROC) analysis, and the immunohistochemistry (IHC) were performed to validate the potential biomarkers. Based on DIA and PRM proteomics and bioinformatics results, we identified POSTN and PAPPA in GS as candidate biomarkers. Their differential expression during ELISA and IHC were generally consistent with our proteomics results. POSTN combined with PAPPA in GS yield a good diagnose fetal CHD with sensitivity of 83.9 %, specificity of 73.9%, and an area under curve (AUC) of 0.842. This is the first study showing that POSTN in GS and AF is associated with fetal CHD. POSTN and PAPPA have huge prospects for application as potential biomarkers in the noninvasive prenatal diagnosis of fetal CHD.

Defining the timeline of periostin upregulation in cardiac fibrosis following acute myocardial infarction in mice

After myocardial infarction (MI), the heart's reparative response to the ischemic insult and the related loss of cardiomyocytes involves cardiac fibrosis, in which the damaged tissue is replaced with a fibrous scar. Although the scar is essential to prevent ventricular wall rupture in the infarction zone, it expands over time to remote, non-infarct areas, significantly increasing the extent of fibrosis and markedly altering cardiac structure. Cardiac function in this scenario deteriorates, thereby increasing the probability of heart failure and the risk of death. Recent works have suggested that the matricellular protein periostin, known to be involved in fibrosis, is a candidate therapeutic target for the regulation of MI-induced fibrosis and remodeling. Different strategies for the genetic manipulation of periostin have been proposed previously, yet those works did not properly address the time dependency between periostin activity and cardiac fibrosis. Our study aimed to fill that gap in knowledge and fully elucidate the explicit timing of cellular periostin upregulation in the infarcted heart to enable the safer and more effective post-MI targeting of periostin-producing cells. Surgical MI was performed in C57BL/6J and BALB/c mice by ligation of the left anterior descending coronary artery. Flow cytometry analyses of cells derived from the infarcted hearts and quantitative real-time PCR of the total cellular RNA revealed that periostin expression increased during days 2-7 and peaked on day 7 post-infarct, regardless of mouse strain. The established timeline for cellular periostin expression in the post-MI heart is a significant milestone toward the development of optimal periostin-targeted gene therapy.

Periostin: biology and function in cancer

Periostin (POSTN), a member of the matricellular protein family, is a secreted adhesion-related protein produced in the periosteum and periodontal ligaments. Matricellular proteins are a nonstructural family of extracellular matrix (ECM) proteins that regulate a wide range of biological processes in both normal and pathological conditions. Recent studies have demonstrated the key roles of these ECM proteins in the tumor microenvironment. Furthermore, periostin is an essential regulator of bone and tooth formation and maintenance, as well as cardiac development. Also, periostin interacts with multiple cell-surface receptors, especially integrins, and triggers signals that promote tumor growth. According to recent studies, these signals are implicated in cancer cell survival, epithelial-mesenchymal transition (EMT), invasion, and metastasis. In this review, we will summarize the most current data regarding periostin, its structure and isoforms, expressions, functions, and regulation in normal and cancerous tissues. Emphasis is placed on its association with cancer progression, and also future potential for periostin-targeted therapeutic approaches will be explored.

Periostin gene expression in neu-positive breast cancer cells is regulated by a FGFR signaling cross talk with TGFβ/PI3K/AKT pathways

Background

Breast cancer is a highly heterogeneous disease with multiple drivers and complex regulatory networks. Periostin (Postn) is a matricellular protein involved in a plethora of cancer types and other diseases. Postn has been shown to be involved in various processes of tumor development, such as angiogenesis, invasion, cell survival and metastasis. The expression of Postn in breast cancer cells has been correlated with a more aggressive phenotype. Despite extensive research, it remains unclear how epithelial cancer cells regulate Postn expression.

Methods

Using murine tumor models and human TMAs, we have assessed the proportion of tumor samples that have acquired Postn expression in tumor cells. Using biochemical approaches and tumor cell lines derived from Neu+ murine primary tumors, we have identified major regulators of Postn gene expression in breast cancer cell lines.

Results

Here, we show that, while the stromal compartment typically always expresses Postn, about 50% of breast tumors acquire Postn expression in the epithelial tumor cells. Furthermore, using an in vitro model, we show a cross-regulation between FGFR, TGFβ and PI3K/AKT pathways to regulate Postn expression. In HER2-positive murine breast cancer cells, we found that basic FGF can repress Postn expression through a PKC-dependent pathway, while TGFβ can induce Postn expression in a SMAD-independent manner. Postn induction following the removal of the FGF-suppressive signal is dependent on PI3K/AKT signaling.

Conclusion

Overall, these results reveal a novel regulatory mechanism and shed light on how breast tumor cells acquire Postn expression. This complex regulation is likely to be cell type and cancer specific as well as have important therapeutic implications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01487-8.

Circulating Levels of IL-13, TGF-β1, and Periostin as Potential Biomarker for Coronary Artery Disease with Acute Heart Failure

Objective

Coronary artery disease (CAD) and associated comorbidities such as heart failure (HF) remain the leading cause of morbidity and mortality worldwide, attributed to, at least partially, the lack of biomarkers for efficient disease diagnosis. The study intended to explore potential biomarkers for predicting the presence of HF in CAD patients.

Methods

According to the presence of HF, 83 CAD patients with HF were assigned to the AHF group and 52 CAD patients without HF to the CAD group. Additionally, healthy controls (n = 52) were those who had received physical examinations at the same period. The serum levels of IL-13, TGF-β1, and periostin were detected by the enzyme-linked immunosorbent assay (ELISA). Left ventricular ejection fraction (LVEF), left ventricular end-diastolic dimension (LVEDD), left ventricle-end diastolic volume (LVEDV), and left ventricular mass index (LVMI) were detected 3 times by color Doppler ultrasound. The predictive values of IL-13, TGF-β1, and periostin methods were compared by receiver-operating characteristic (ROC) analysis and the area under the curve (AUC).

Results

Increased levels of IL-13, TGF-β1, and periostin were noted in the AHF group than in the control and CAD groups (p < 0.001); the CAD group showed higher levels of IL-13, TGF-β1, and periostin than the control group (p < 0.001). Based on the NYHA classification, there were 33 cases with grade II, 28 cases with grade III, and 22 cases with grade IV among 83 CAD patients with HF. It was found that the serum levels of IL-13, TGF-β1, and periostin were higher in the AHF-IV group than in the AHF-III and AHF-II groups (p < 0.001); these levels were also higher in the AHF-III group than in the AHF-II group (p < 0.001). The periostin level was positively correlated with the levels of IL-13 (r = 0.458) and TGF-β1 (r = 0.569) in CAD patients with AHF. Besides, the serum levels of periostin (r = -0.425), IL-13 (r = -0.341), and TGF-β1 (r = -0.435) were negatively correlated with the LVEF of CAD patients with AHF, respectively. When IL-13, TGF-β1, and periostin levels were used to predict the presence of AHF in CAD patients in combination, the sensitivity and specificity were 75.9% and 90.38%, respectively, with the AUC of 0.906 (95% CI: 0.912–0.996).

Conclusion

These data reveal that IL-13, TGF-β1, and periostin levels might be associated with the occurrence of AHF in CAD patients and their combination shows the predictive value for the presence of AHF in CAD patients.

Spatiotemporal extracellular matrix modeling for in situ cell niche studies

Extracellular matrix (ECM) components govern a range of cell functions, such as migration, proliferation, maintenance of stemness, and differentiation. Cell niches that harbor stem-/progenitor cells, with matching ECM, have been shown in a range of organs, although their presence in the heart is still under debate. Determining niches depends on a range of in vitro and in vivo models and techniques, where animal models are powerful tools for studying cell-ECM dynamics; however, they are costly and time-consuming to use. In vitro models based on recombinant ECM proteins lack the complexity of the in vivo ECM. To address these issues, we present the spatiotemporal extracellular matrix model for studies of cell-ECM dynamics, such as cell niches. This model combines gentle decellularization and sectioning of cardiac tissue, allowing retention of a complex ECM, with recellularization and subsequent image processing using image stitching, segmentation, automatic binning, and generation of cluster maps. We have thereby developed an in situ representation of the cardiac ECM that is useful for assessment of repopulation dynamics and to study the effect of local ECM composition on phenotype preservation of reseeded mesenchymal progenitor cells. This model provides a platform for studies of organ-specific cell-ECM dynamics and identification of potential cell niches.

Periostin/Filamin-A: A Candidate Central Regulatory Axis for Valve Fibrogenesis and Matrix Compaction

BACKGROUND

Discoveries in the identification of transcription factors, growth factors and extracellular signaling molecules have led to the detection of downstream targets that modulate valvular tissue organization that occurs during development, aging, or disease. Among these, matricellular protein, periostin, and cytoskeletal protein filamin A are highly expressed in developing heart valves. The phenotype of periostin null indicates that periostin promotes migration, survival, and differentiation of valve interstitial cushion cells into fibroblastic lineages necessary for postnatal valve remodeling/maturation. Genetically inhibiting filamin A expression in valve interstitial cushion cells mirrored the phenotype of periostin nulls, suggesting a molecular interaction between these two proteins resulted in poorly remodeled valve leaflets that might be prone to myxomatous over time. We examined whether filamin A has a cross-talk with periostin/signaling that promotes remodeling of postnatal heart valves into mature leaflets.

RESULTS

We have previously shown that periostin/integrin-β1 regulates Pak1 activation; here, we revealed that the strong interaction between Pak1 and filamin A proteins was only observed after stimulation of VICs with periostin; suggesting that periostin/integrin-β-mediated interaction between FLNA and Pak1 may have a functional role in vivo. We found that FLNA phosphorylation (S2152) is activated by Pak1, and this interaction was observed after stimulation with periostin/integrin-β1/Cdc42/Rac1 signaling; consequently, FLNA binding to Pak1 stimulates its kinase activity. Patients with floppy and/or prolapsed mitral valves, when genetically screened, were found to have point mutations in the filamin A gene at P637Q and G288R. Expression of either of these filamin A mutants failed to increase the magnitude of filamin A (S2152) expression, Pak1-kinase activity, actin polymerization, and differentiation of VICs into mature mitral valve leaflets in response to periostin signaling.

CONCLUSION

PN-stimulated bidirectional interaction between activated FLNA and Pak1 is essential for actin cytoskeletal reorganization and the differentiation of immature VICs into mature valve leaflets.

Extracellular Matrix in Calcific Aortic Valve Disease: Architecture, Dynamic and Perspectives

Calcific Aortic Valve Disease (CAVD) is the most common valvular heart disease in developed countries and in the ageing population. It is strongly correlated to median age, affecting up to 13% of the population over the age of 65. Pathophysiological analysis indicates CAVD as a result of an active and degenerative disease, starting with sclerosis and chronic inflammation and then leaflet calcification, which ultimately can account for aortic stenosis. Although CAVD has been firstly recognized as a passive event mostly resulting from a degenerative aging process, much evidences suggests that calcification arises from different active processes, involving both aortic valve-resident cells (valve endothelial cells, valve interstitial cells, mesenchymal stem cells, innate immunity cells) and circulating cells (circulating mesenchymal cells, immunity cells). Moreover, a role for the cell-derived "matrix vesicles" and extracellular matrix (ECM) components has also been recognized. The aim of this work is to review the cellular and molecular alterations occurring in aortic valve during CAVD pathogenesis, focusing on the role of ECM in the natural course of the disease.