Secreted Frizzled-Related Protein 1 Promotes Odontoblastic Differentiation and Reparative Dentin Formation in Dental Pulp Cells

Evaluation of the differences in proteomics of high-quality bovine colostrum and low-quality bovine colostrum

BACKGROUND

Although there are studies on colostrum and milk proteomics of different species in the literature, there is no published report about different quality bovine colostrums' proteomics.

OBJECTIVES

The aim of this study was to compare the proteome content of high- and low-quality bovine colostrums for the first time.

METHODS

Colostrum samples were collected from 32 Holstein cows from the same farm that had just calved. Brix% levels of colostrums were measured, and then, those with a Brix% value of ≥27% were classified as high-quality and those with a Brix% value of <22% as low-quality. Three samples from high-quality and low-quality colostrums were selected and proteomic analyses were performed by pooling separately.

RESULTS

Totally 95 proteins were identified in the colostrums, and 19 of them showed significant changes between high- and low-quality colostrums. Expressions in colostrum of glycosylation-dependent cell adhesion molecule-1, cofilin-1, alpha-S2-casein, alpha-lactalbumin, alpha-1B-glycoprotein, actin_cytoplasmic-1, nucleobindin-1, cathelicidin-4, inter-alpha-trypsin inhibitor heavy chain H4, chitinase-3-like protein 1 and monocyte differentiation antigen CD14 were lower, whereas tetranectin, secreted frizzled-related protein-1 (SFRP1), perilipin-2, coatomer subunit epsilon (COPE), butyrophilin subfamily 1 member A1, polyubiquitin-B, lactadherin and albumin levels were higher in high-quality colostrum than low-quality colostrum. Moreover, SFRP1, COPE and cathelicidin-4 proteins were identified for the first time in bovine colostrum. In high-quality colostrum, the most prominently down-regulated proteins were cathelicidin-4 (26.01-fold) and cofilin-1 (17.42-fold), and the most prominently up-regulated proteins were COPE (3.37-fold) and tetranectin (3.07-fold).

CONCLUSIONS

It was detected that the proteome contents of high- and low-quality bovine colostrums were different from each other. As new functions are added to the protein databases regarding these proteins detected in colostrums, the interactions of proteins with each other and with other molecules will be detailed and the effects of high-quality colostrums on passive transfer immunity and calf health will be understood in full detail.

Targeting the cochlin/SFRP1/CaMKII axis in the ocular posterior pole prevents the progression of nonpathologic myopia

Myopia is a major public health issue. However, interventional modalities for nonpathologic myopia are limited due to its complicated pathogenesis and the lack of precise targets. Here, we show that in guinea pig form-deprived myopia (FDM) and lens-induced myopia (LIM) models, the early initiation, phenotypic correlation, and stable maintenance of cochlin protein upregulation at the interface between retinal photoreceptors and retinal pigment epithelium (RPE) is identified by a proteomic analysis of ocular posterior pole tissues. Then, a microarray analysis reveals that cochlin upregulates the expression of the secreted frizzled-related protein 1 (SFRP1) gene in human RPE cells. Moreover, SFRP-1 elevates the intracellular Ca2+ concentration and activates Ca2+/calmodulin-dependent protein kinase II (CaMKII) signaling in a simian choroidal vascular endothelial cell line, and elicits vascular endothelial cell dysfunction. Furthermore, genetic knockdown of the cochlin gene and pharmacological blockade of SFRP1 abrogates the reduced choroidal blood perfusion and prevents myopia progression in the FDM model. Collectively, this study identifies a novel signaling axis that may involve cochlin in the retina, SFRP1 in the RPE, and CaMKII in choroidal vascular endothelial cells and contribute to the pathogenesis of nonpathologic myopia, implicating the potential of cochlin and SFRP1 as myopia interventional targets.

Dopamine is involved in reparative dentin formation through odontoblastic differentiation of dental pulp stem cells

Conventional direct pulp-capping materials induce pulp cells to secrete various biomolecules in pulp tissues that promote reparative dentin formation through induction of odontoblastic differentiation of dental pulp stem cells (DPSCs). However, these biomolecules sometimes induce bone-like dentin with poor sealing properties. Therefore, exploration of biomolecules that allow tight sealing by tubular reparative dentin is required. We recently reported that dopamine (DA) is involved in dentinogenesis. Hence, we investigated the effect of DA on odontoblastic differentiation of DPSCs and reparative dentin formation. Both tyrosine hydroxylase (TH), a DA synthetase, and DA were expressed in odontoblast-like cells in vivo. In vitro, their expression was increased during odontoblastic differentiation of DPSCs. Furthermore, TH-overexpressing DPSCs had promoted odontoblastic differentiation and DA production. Moreover, DA stimulation promoted their differentiation and induced tubular reparative dentin. These results suggest that DA produced by TH is involved in odontoblastic differentiation of DPSCs and has an inductive capacity for reparative dentin formation similar to primary dentin. This study may lead to the development of therapy to preserve vital pulp tissues.

PAX9 Is Involved in Periodontal Ligament Stem Cell-like Differentiation of Human-Induced Pluripotent Stem Cells by Regulating Extracellular Matrix

Periodontal ligament stem cells (PDLSCs) play central roles in periodontal ligament (PDL) tissue homeostasis, repair, and regeneration. Previously, we established a protocol to differentiate human-induced pluripotent stem cell-derived neural crest-like cells (iNCs) into PDLSC-like cells (iPDLSCs) using human PDL cell-derived extracellular matrix (ECM). However, it remained unclear what factors principally regulate the differentiation of iNCs into iPDLSCs. In this study, we aimed to identify the transcription factor regulating production of human PDL cell-derived ECM, which is responsible for the generation of iPDLSCs. We cultured iNCs on ECMs of two human PDL cell lines (HPDLC-3S and HPDLC-3U) and of human dermal fibroblasts (HDF). iNCs cultured on HPDLC-3U demonstrated higher iPDLSC-associated gene expression and mesenchymal differentiation capacity than cells cultured on HDF or HPDLC-3S. The transcription factor PAX9 was highly expressed in HPDLC-3U compared with HDF and HPDLC-3S. iNCs cultured on siPAX9-transfected HPDLC-3U displayed downregulation of iPDLSC-associated marker expression and adipocytic differentiation capacity relative to controls. Our findings suggest that PAX9 is one of the transcription factors regulating ECM production in human PDL cells, which is responsible for the differentiation of iNCs into iPDLSCs.