ROCK inhibition modulates the senescence‐associated secretory phenotype (SASP) in oral keratinocytes

Senescent cells accumulate in different organs and develop a senescence‐associated secretory phenotype (SASP), associated with the development of age‐related pathologies. The constitution of the SASP varies among cell types and with the method of senescence induction; nevertheless, there is substantial overlap among SASPs, especially the presence of pro‐inflammatory cytokines such as IL‐1β, IL‐1α, IL‐6 and IL‐8. These cytokines are highly conserved among SASPs and are implicated in the development of several cancers. Here, we report that ROCK inhibition by Y‐27632 reduces levels of IL‐1α, IL‐1β, IL‐6 and IL‐8 secreted by senescent normal and dysplastic oral keratinocytes without affecting the permanent cell growth arrest. The data indicate some inflammatory genes downregulated by Y‐27632 remain downregulated even after repeated passage in the absence of Y‐27632. We propose ROCK kinase inhibition as a novel alternative to current strategies to modulate the inflammatory components of the SASP, without compromising the permanent cell growth arrest. This observation potentially has wide clinical applications, given the involvement of senescence in cancer and a wide range of age‐related disease. It also suggests care should be exercised when using Y‐27632 to facilitate cell expansion of primary cells, as its effects on gene expression are not entirely reversible

Laminin-511 and laminin-521-based matrices for efficient hepatic specification of human pluripotent stem cells

Human pluripotent stem cells (hPSCs) have gained a solid foothold in basic research and drug industry as they can be used in vitro to study human development and have potential to offer limitless supply of various somatic cell types needed in drug development. Although the hepatic differentiation of hPSCs has been extensively studied, only a little attention has been paid to the role of the extracellular matrix. In this study we used laminin-511, laminin-521, and fibronectin, found in human liver progenitor cells, as culture matrices for hPSC-derived definitive endoderm cells. We observed that laminin-511 and laminin-521 either alone or in combination support the hepatic specification and that fibronectin is not a vital matrix protein for the hPSC-derived definitive endoderm cells. The expression of the laminin-511/521-specific integrins increased during the definitive endoderm induction and hepatic specification. The hepatic cells differentiated on laminin matrices showed the upregulation of liver-specific markers both at mRNA and protein levels, secreted human albumin, stored glycogen, and exhibited cytochrome P450 enzyme activity and inducibility. Altogether, we found that laminin-511 and laminin-521 can be used as stage-specific matrices to guide the hepatic specification of hPSC-derived definitive endoderm cells. 2016 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND licensePeer reviewe

Difference in EGFR expression and mean vascular density in normal oral mucosa, oral epithelial dysplasia and oral squamous cell carcinoma.

To evaluate the expression of the epidermal growth factor receptor (EGFR) and mean vascular density (MVD) in normal oral mucosa (NOM), oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). Material and methods: Descriptive case study. Nineteen histological samples diagnosed with NOM, 18 diagnosed with OED, and 19 with OSCC, were analyzed with immunohistochemistry against EGFR and CD31. EGFR expression was evaluated by extent and intensity of its expression in normal, dysplastic and neoplastic epithelium. MVD was determined through the detection of blood vessels by antibodies against CD31. Results: Extension of EGFR expression was highest in OSCC followed by OED and lowest in NOM, resulting in significant different between the degrees of extension (p<0.001). Intensity of EGFR was similar in NOM, OED and OSCC, without differences in its expression (p=0.533). Differences in MVD were found between NOM and OSCC groups (p<0.01), and between OED and OSCC groups (p<0.01), with no differences between NOM and OED groups (p=0.91). MVD was 21.17±4.98 in NOM, 23.40±5.77 in OED and 33.92±8.39 in OSCC. Conclusion: EGFR is expressed in normal, dysplastic or neoplastic oral epithelium. However, the extent of its expression is greater as malignancy increases. MVD varies according to the diagnosis

Impact of 1% malic acid spray on the oral health-related quality of life of patients with xerostomia

Indexación: Scopus.Dry mouth sensation, also known as xerostomia, is a common clinical problem with an increasing prevalence. Although recent studies have reported promissory results of malic acid, none have evaluated the impact of malic acid on the oral health-related quality of life (OHRQoL) of patients with xerostomia. Thus, this study aimed to evaluate the impact of 1% malic acid, combined with fluoride and xylitol, on the OHRQoL of patients with xerostomia. We enrolled 70 patients and randomly allocated them into two groups: the intervention group (applied topical sialogogue with 1% malic acid) and the control group (applied a placebo). We assessed the OHRQoL and severity of xerostomia before and after treatment with the Spanish version of the Oral Health Impact Profile-14 questionnaire (OHIP-14sp) and a visual analogue scale (VAS), respectively. In addition, stimulated and non-stimulated salivary flow rates before and after treatments were also measured. In total, 60 patients completed the study. According to the VAS, both sprays significantly improved dry mouth sensation (P 0.05). Furthermore, non-stimulated salivary flow rates significantly increased in the intervention group from 0.25 ± 0.22 to 0.33 ± 0.33 mL/min (P < 0.001). Overall, this study demonstrated that malic acid improves the OHRQoL and dry mouth sensation in patients with xerostomia. © 2018, Nihon University, School of Dentistry. All rights reserved.https://www.jstage.jst.go.jp/article/josnusd/60/2/60_17-0164/_articl

Chloroplasts assemble the major subunit FaeG of Escherichia coli F4 (K88) fimbriae to strand-swapped dimers.

F4 fimbriae encoded by the fae operon are the major colonization factors associated with porcine neonatal and postweaning diarrhoea caused by enterotoxigenic Escherichia coli (ETEC). Via the chaperone/usher pathway, the F4 fimbriae are assembled as long polymers of the major subunit FaeG, which also possesses the adhesive properties of the fimbriae. Intrinsically, the incomplete fold of fimbrial subunits renders them unstable and susceptible to aggregation and/or proteolytic degradation in the absence of a specific periplasmic chaperone. In order to test the possibility of producing FaeG in plants, FaeG expression was studied in transgenic tobacco plants. FaeG was directed to different subcellular compartments by specific targeting signals. Targeting of FaeG to the chloroplast results in much higher yields than FaeG targeting to the endoplasmic reticulum or the apoplast. Two chloroplast-targeted FaeG variants were purified from tobacco plants and crystallized. The crystal structures show that chloroplasts circumvent the absence of the fimbrial assembly machinery by assembling FaeG into strand-swapped dimers. Furthermore, the structures reveal how FaeG combines the structural requirements of a major fimbrial subunit with its adhesive role by grafting an additional domain on its Ig-like core