The trichoplein–AurA pathway must suppress primary cilia assembly in order for cells to exit G1.

SummaryThe keratin cytoskeleton performs several functions in epithelial cells and provides regulated interaction sites for scaffold proteins, including trichoplein. Previously, we found that trichoplein was localized on keratin intermediate filaments and desmosomes in welldifferentiated, non-dividing epithelia. Here, we report that trichoplein is widely expressed and has a major function in the correct localization of the centrosomal protein ninein in epithelial and non-epithelial cells. Immunocytochemical analysis also revealed that this protein is concentrated at the subdistal to medial zone of both mother and daughter centrioles. Trichoplein binds the centrosomal proteins Odf2 and ninein, which are localized at the distal to subdistal ends of the mother centriole. Trichoplein depletion abolished the recruitment of ninein, but not Odf2, specifically at the subdistal end. However, Odf2 depletion inhibited the recruitment of trichoplein to a mother centriole, whereas ninein depletion did not. In addition, the depletion of each molecule impaired MT anchoring at the centrosome. These results suggest that trichoplein has a crucial role in MT-anchoring activity at the centrosome in proliferating cells, probably through its complex formation with Odf2 and ninein.

Temporomandibular disorders (TMD) are a common stomatognathic disease affecting all age groups. Patients with internal derangement (ID) or osteoarthritis (OA) of temporomandibular joint (TMJ) often have TMJ synovitis. When TMJ synovial membrane is damaged, many inflammatory cytokines are produced and secreted from TMJ synoviocytes to synovial fluid of TMJ. It has been widely reported that many kinds of biologic factors are produced from TMJ synoviocytes stimulated with interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. One of the major symptoms of TMD is pain of the TMJ. Many study groups have studied relations between the development of TMJ pain and biologic factors secreted into synovial fluid of TMJ. Here, we summarize previous reports trying to elucidate this correlation. On the other hand, it has been reported that a new molecular mechanism of IL-1beta secretion called inflammasome is involved in several diseases with sterile inflammation. Because TMJ synovitis with ID and OA of TMJ is also sterile inflammation, inflammasome may be involved in the development of TMJ synovial inflammation. This review describes some molecular mechanisms underlying inflammation in TMJ, especially in TMJ synovitis, which may be useful for the development of new therapies against TMD.

Immunosuppressive/anti-inflammatory macrophage (Mφ), M2-Mφ that expressed the typical M2-Mφs marker, CD206, and anti-inflammatory cytokine, interleukin (IL)-10, is beneficial and expected tool for the cytotherapy against inflammatory diseases. Here, we demonstrated that bone marrow-derived lineage-positive (Lin+) blood cells proliferated and differentiated into M2-Mφs by cooperation with the bone marrow-derived mesenchymal stem cells (MSCs) under hypoxic condition: MSCs not only promoted proliferation of undifferentiated M2-Mφs, pre-M2-Mφs, in the Lin+ fraction via a proliferative effect of the MSCs-secreted macrophage colony-stimulating factor, but also promoted M2-Mφ polarization of the pre-M2-Mφs through cell-to-cell contact with the pre-M2-Mφs. Intriguingly, an inhibitor for intercellular adhesion molecule (ICAM)-1 receptor/lymphocyte function-associated antigen (LFA)-1, Rwj50271, partially suppressed expression of CD206 in the Lin+ blood cells but an inhibitor for VCAM-1 receptor/VLA-4, BIO5192, did not, suggesting that the cell-to-cell adhesion through LFA-1 on pre-M2-Mφs and ICAM-1 on MSCs was supposed to promoted the M2-Mφ polarization. Thus, the co-culture system consisting of bone marrow-derived Lin+ blood cells and MSCs under hypoxic condition was a beneficial supplier of a number of M2-Mφs, which could be clinically applicable to inflammatory diseases.

We investigated whether transforming growth factor (TGF)-β1 promoted epithelial-mesenchymal transition (EMT) and migration of human oral squamous cell carcinoma (hOSCC) cells. Among 6 hOSCC cell lines investigated, Smad2 phosphorylation and TGF-β target genes expression were most clearly upregulated following TGF-β1 stimulation in HSC-4 cells, indicating that HSC-4 cells were the most responsive to TGF-β1. In addition, the expression levels of the mesenchymal markers N-cadherin and vimentin were most clearly induced in HSC-4 cells among the hOSCC cell lines by TGF-β1 stimulation. Interestingly, E-cadherin and β-catenin at the cell surface were internalized in HSC-4 cells stimulated with TGF-β1. In addition, the expression levels of the EMT-related transcription factor Slug was significantly upregulated on TGF-β1 stimulation. Moreover, the downregulation of Slug by RNA interference clearly inhibited the TGF-β1-induced expression of mesenchymal marker and the migration of HSC-4 cells. Proteomics analysis also revealed that the expression levels of integrin α3β1-targeted proteins were upregulated in TGF-β1-stimulated HSC-4 cells. Neutral antibodies against integrin α3 and β1, as well as a focal adhesion kinase (FAK) inhibitor, clearly suppressed TGF-β1-induced cell migration. These results suggest that the EMT and integrin α3β1/FAK pathway-mediated migration of TGF-β1-stimulated HSC-4 hOSCC cells is positively controlled by Slug.

Increased gene expression levels of sodium-glucose cotransporter 1 (SGLT1) are associated with hypertrophic and ischemic cardiomyopathy. However, it remains unclear whether chronic pressure overload increases SGLT1 expression, which in turn induces hypertrophic cardiomyopathy. We hypothesized that pressure overload could increase SGLT1 gene expression, leading to the development of hypertrophic cardiomyopathy.To create pressure overload-induced cardiomyopathy, transverse aortic constriction (TAC) was performed in SGLT1-deficient (SGLT1) and wild-type (WT) mice. Six weeks after surgery, all mice were investigated. We observed a reduction of left ventricular fractional shortening and left ventricular dilatation in TAC-operated WT but not in TAC-operated SGLT1 mice. SGLT1, interleukin 18, connective tissue growth factor, and collagen type 1 gene expression levels were increased in TAC-operated WT mouse hearts compared with that of sham-operated WT mouse hearts. Moreover, heart/body weight ratio and ventricular interstitial fibrosis were increased in TAC-operated WT mice compared with that of sham-operated WT mice. Interestingly, these factors did not increase in TAC-operated SGLT1 mice compared with that of sham-operated WT and SGLT1 mice. Phenylephrine, an adrenergic α receptor agonist, caused cardiomyocyte hypertrophy in neonatal WT mouse hearts to a significantly larger extent than in neonatal SGLT1 mouse hearts.In conclusion, the results indicate that chronic pressure overload increases SGLT1 and IL-18 gene expressions, leading to the development of hypertrophic cardiomyopathy. These results make SGLT1 a potential candidate for the therapeutic target for hypertension-induced cardiomyopathy.

ObjectiveThe periodontal ligament (PDL) is a fibrous connective tissue composed of heterogeneous cell types, including PDL fibroblasts. It is not clear whether cells within the PDL fibroblast population retain the potency to differentiate into other cell types. DesignIn the present study, clonal cell lines, derived from Clawn miniature swine PDLs, were established by gene transfection for a human telomerase reverse transcriptase, and characterized. ResultsThese cell lines, denoted TesPDL1-4, had PDL fibroblasts that showed fibroblastic morphology and expressed procollagen α1(I), osteopontin, periostin and alkaline phosphatase mRNA. Under the specific culture conditions, TesPDL3 cells also have the ability to express CD31, vascular endothelial cadherin, von Willebrand factor, osteocalcin, and to form extracellular mineralized nodules. ConclusionsOur data indicate that TesPDL3 cells have unique properties of expressing several phenotype of fibroblasts, vascular endothelial cells and osteoblasts in cultures.2

The periodontal ligament (PDL) is a fibrous connective tissue that attaches the tooth to the alveolar bone. We previously demonstrated the ability of PDL fibroblast-like cells to construct an endothelial cell (EC) marker-positive blood vessel-like structure, indicating the potential of fibroblastic lineage cells in PDL tissue as precursors of endothelial progenitor cells (EPCs) to facilitate the construction of a vascular system around damaged PDL tissue. A vascular regeneration around PDL tissue needs proliferation of vascular progenitor cells and the subsequent differentiation of the cells. Transforming growth factor-β (TGF-β) is known as an inducer of endothelial-mesenchymal transition (EndMT), however, it remains to be clarified what kinds of TGF-β signals affect growth and mesenchymal differentiation of PDL-derived EPC-like fibroblastic cells. Here, we demonstrated that TGF-β1 not only suppressed the proliferation of the PDL-derived EPC-like fibroblastic cells, but also induced smooth muscle cell (SMC) markers expression in the cells. On the other hand, TGF-β1 stimulation suppressed EC marker expression. Intriguingly, overexpression of Smad7, an inhibitor for TGF-β-induced Smad-dependent signaling, suppressed the TGF-β1-induced growth inhibition and SMC markers expression, but did not the TGF-β1-induced downregulation of EC marker expression. In contrast, p38 mitogen-activated protein kinase (MAPK) inhibitor SB 203580 suppressed the TGF-β1-induced downregulation of EC marker expression. In addition, the TGF-β1-induced SMC markers expression of the PDL-derived cells was reversed upon stimulation with fibroblast growth factor (FGF), suggesting that the TGF-β1 might not induce terminal SMC differentiation of the EPC-like fibroblastic cells. Thus, TGF-β1 not only negatively controls the growth of PDL-derived EPC-like fibroblastic cells via a Smad-dependent manner but also positively controls the SMC-differentiation of the cells possibly at the early stage of the translineage commitment via Smad- and p38 MAPK-dependent manners.