Upregulation of class II beta-tubulin expression in differentiating keratinocytes

Transcriptome Differences in Pig Tracheal Epithelial Cells in Response to Pasteurella Multocida Infection

Pasteurella multocida generally colonizes mammalian/bird respiratory tracts and mainly causes respiratory disorders in both humans and animals. To date, the effects of P. multocida infection on the respiratory epithelial barriers and molecules in host respiratory epithelial cells in their response to P. multocida infection are still not well-known. In this study, we used newborn pig tracheal epithelial (NPTr) cells as an in vitro model to investigate the effect of P. multocida infection on host respiratory epithelial barriers. By detecting the transepithelial electrical resistance (TEER) values of NPTr cells and the expression of several known molecules associated with cell adherens and junctions, we found that P. multocida infection disrupted the barrier functions of NPTr cells. By performing RNA sequencing (RNA-Seq), we determined 30 differentially expressed genes (DEGs), including the vascular endothelial growth factor A (VEGFA) encoding gene VEGFA, which participated in biological processes (GO:0034330, GO:0045216, and GO:0098609) closely related to epithelial adhesion and barrier functions. These 30 DEGs participated in 22 significant signaling pathways with a p-value < 0.05, including the transforming growth factor (TGF)-beta signaling pathway (KEGG ID: ssc04350), hypoxia-inducible factor 1 (HIF-1) signaling pathway (KEGG ID: ssc04066), epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor resistance (KEGG ID: ssc01521), tumor necrosis factor (TNF) signaling pathway (KEGG ID: ssc04668), and mitogen-activated protein kinase (MAPK) signaling pathway (KEGG ID: ssc04010), which are reported to have roles in contributing to the production of inflammatory factors as well as the regulation of epithelial adhesion and barrier function in other tissues and organisms. The results presented in this study may help improve our understanding of the pathogenesis of P. multocida.

EP4 and Class III β-Tubulin Expression in Uterine Smooth Muscle Tumors: Implications for Prognosis and Treatment

The microtubule-stabilizing agent docetaxel in combination with gemcitabine represents one of the most effective regimens against the aggressive gynecologic tumor leiomyosarcoma (LMS). Upregulation of class III β-tubulin has previously been shown to confer taxane resistance in a variety of human cancers. Prostaglandin E₂ receptor EP4 is linked to progression of a variety of human cancers and may represent a novel target for tumor inhibition in LMS. We evaluated the hypotheses that EP4 and class III β-tubulin have increased expression in LMS in comparison to normal myometrium or benign tumors and that expression of class III β-tubulin correlates with resistance to taxanes and poor clinical outcome. Gene expression was examined using TCGA data and correlated with clinicopathologic outcome which demonstrated that class III β-tubulin is more highly expressed in more aggressive sarcomas with EP4 being widely expressed in all subtypes of sarcoma. Immunohistochemistry for EP4 and class III β-tubulin was performed on patients with LMS, leiomyomatosis/STUMP, leiomyoma, and normal myometrium. Expression of EP4 and class III β-tubulin were characterized for cell lines SK-UT-1, SK-UT-1B, and PHM-41 and these cell lines were treated with docetaxel alone and in combination with EP4 inhibitors. In taxane-resistant cell lines that overexpress class III β-tubulin and EP4, treatment with EP4 inhibitor resulted in at least 2-fold sensitization to docetaxel. Expression of class III β-tubulin and EP4 in LMS may identify patients at risk of resistance to standard chemotherapies and candidates for augmentation of therapy through EP4 inhibition.

A potential new approach for treating systemic sclerosis: Dedifferentiation of SSc fibroblasts and change in the microenvironment by blocking store-operated Ca2+ entry

Transforming growth factor-β (TGF-β) is an important target for treating systemic sclerosis (SSc). However, our study revealed three levels of TGF-β1 expression in SSc patients, indicating that inhibiting TGF-β is not sufficient to treat SSc. A previous clinical trial also displayed disappointing results. Thus, our study attempted to search for a potential novel approach. Ingenuity Pathway Analysis (IPA) indicated that the SSc pathological pathways were closely associated with store-operated Ca²⁺ entry (SOCE)-regulated signals, and SOCE activity was found to be increased in SSc fibroblasts. Further treatment of SSc fibroblasts with SOCE inhibitors, 2APB, and associated calcium channel inhibitors SKF96365, and indomethacin, showed that the SOCE inhibitors selectively decreased fibrosis markers and altered the cell morphology. Consequently, SOCE inhibitors, especially 2APB and indomethacin, caused the dedifferentiation of SSc fibroblasts via cytoskeleton remodeling and altered collagen secretion and restored the cell mobility. We further explained SSc pathogenesis as fibroblast differentiation with SOCE. Treatment with exogenous factors, gelatin-1, FAM20A and human albumin, which were identified from the conditioned medium of SSc fibroblasts, was important for regulating the differentiation of fibroblasts with higher levels of SOCE and α-SMA. Conclusively, to treat SSc, blockage of the increased SOCE activity in SSc induces the dedifferentiation of SSc fibroblasts and simultaneously changes the extracellular matrix (ECM) structure to limit SSc pathogenesis.

Post-translational control of Myc function during differentiation

Myc proteins are deeply involved in multiple biological processes including cell proliferation, growth, metabolism, apoptosis, differentiation, and tumorigenesis. Paradoxically, Myc proteins have been found to be capable of both inhibiting and facilitating differentiation depending on the biological context. Recently we identified a new mode of Myc regulation in differentiating muscle cells in which c-Myc protein is proteolytically cleaved by calcium-dependent calpains in the cytoplasm. This cleavage serves two purposes. First, it inactivates the transcriptional function of Myc by removing its C-terminus, a region responsible for the interaction of Myc with Max and DNA. Second, it alters cytoskeletal architecture and accelerates muscle differentiation through the activity of the remaining N-terminal cleavage product (termed Myc-nick). Here we discuss the roles and regulation of full-length Myc and Myc-nick in terminal differentiation and propose a model in which calpain-mediated cleavage of Myc operates as a functional switch.

Class II beta-tubulin is a novel marker for human tonsillar M cells and follicular dendritic cells

OBJECTIVE

Membranous (M) cell of the human palatine tonsil is an antigen entry site for mucosal infection, but its location is obscure in histological sections. Recently, a microarray analysis has demonstrated that clusterin, annexin A5, CD44, MMP14, and beta-tubulin are candidate genes of M cell marker in mice. Among these genes, we here describe class II beta-tubulin as a new marker for human tonsillar M cells and follicular dendritic cells (FDCs), and present its usefulness for diagnosis of angioimmunoblastic T-cell lymphomas (AILTs).

MATERIALS AND METHODS

Immunohistochemistry and Western blotting for class II beta-tubulin were performed using 81 cases of lymphoid, gastrointestinal and thyroid tissues, and an FDC cell line, respectively. Double immunostaining with clusterin and class II beta-tubulin were carried out.

RESULTS

Class II beta-tubulin localized the M cells and FDCs in the palatine tonsils (10/10, 100%) and adenoids (10/10, 100%). It was colocalized with clusterin in the palatine tonsils. However, class II beta-tubulin staining did not identify intestinal M cells in the intestines. Immunoblot analysis revealed that class II beta-tubulin expression was upregulated in HK cells, a normal FDC cell line. Class II beta-tubulin immunostaining highlighted hyperplastic FDC meshworks in all AILTs (14/14, 100%).

CONCLUSION

Class II beta-tubulin is a specific histochemical marker for human tonsillar M cells and FDCs. Thus, class II beta-tubulin immunostaining may be useful to identify tonsillar M cells and to diagnose FDC proliferative lesions such as AILT.

Expression of class II ?-tubulin in non-melanoma cutaneous tumors

BACKGROUND

Different combinations of beta-tubulin isotypes contribute to the diverse functions of microtubules (MTs). Class II beta-tubulin (class II tubulin) is up-regulated in differentiated keratinocytes. In contrast, the expression of class II tubulin in follicular differentiation and cutaneous tumors has not been studied.

METHODS

The immunohistochemical expression of class II tubulin was investigated in 117 cutaneous tumors: 30 squamous cell carcinomas (SCCs), seven keratoacanthomas (KAs), 57 basal cell carcinomas (BCCs), 23 trichoepitheliomas (TEs), and in the adjacent non-neoplastic skin.

RESULTS

Class II tubulin was expressed in the keratinocytes of the granular layer, melanocytes, hair cortical and cuticular cells, inner root sheath (IRS), companion layer (CL) of the outer root sheath (ORS), and mesenchymal cells with Schwannian or myogenic differentiation. Moreover, class II tubulin expression was increased in the areas of squamous or follicular differentiation in cutaneous tumors. On grading the follicular differentiation or myofibroblastic response with anti-class II tubulin, TE showed follicular differentiation more frequently (p < 0.001) with less of a myofibroblastic response (p = 0.001) than BCC.

CONCLUSIONS

Class II tubulin expression is closely related to squamous or follicular differentiation and may be helpful in distinguishing most SCCs from KAs and BCC from TE. However, it does not reliably distinguish well-differentiated, crateriform SCC from KA.