Expression K1 Research Articles

Excess Transforming Growth Factor-α Changed the Cell Properties of Corneal Epithelium and Stroma.

PurposeThis study is to investigate the corneal anomaly caused by excess transforming growth factor-α (TGF-α) during mouse development.MethodsBitransgenic KeraRT/TGF-α mice, generated via cross-mating tetO-TGF-α and KeraRT mice, were induced to overexpress TGF-α by doxycycline commencing at embryonic day 0 or postnatal day 0 to different developmental stages. Bitransgenic mice with doxycycline induction were defined as TGF-αECK mice (TGF-α excess expression by corneal keratocytes). Mouse eyes were examined by hematoxylin and eosin staining, immunofluorescent staining and transmission electron microscopy. Protein and RNA from mouse cornea were subjected to western blotting and real-time quantitative polymerase chain reaction.ResultsIn TGF-αECK mice, TGF-α overexpression resulted in corneal opacity. Excess TGF-α initially caused corneal epithelial hyperplasia and subsequent epithelium degeneration as the mouse developed, which was accompanied by gradually diminished K12 expression from the periphery of corneal epithelium and increased K13 expression toward the corneal center. Interestingly, K14 was detected in all layers of corneal epithelium of TGF-αECK mice, whereas it was limited at basal layer of controls. Transmission electron microscopy showed desmosome loss between corneal epithelial cells of TGF-αECK mice. In TGF-αECK mice, keratocan expression was abolished; α-SMA expression was increased while expression of Col1a1, Col1a2, and Col5a1 was diminished. Cell proliferation increased in the corneal epithelium and stroma, but not in the endothelium of TGF-αECK mice.ConclusionsExcess TGF-α had detrimental effects on corneal morphogenesis during mouse development in that it changed the cell fate of corneal epithelial cells to assume conjunctival phenotypic expression of K13, and keratocytes to myofibroblast phenotype.

An unbiased high-throughput drug screen reveals a potential therapeutic vulnerability in the most lethal molecular subtype of pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer‐related deaths in the United States by 2020, due in part to innate resistance to widely used chemotherapeutic agents and limited knowledge about key molecular factors that drive tumor aggression. We previously reported a novel negative prognostic biomarker, keratin 17 (K17), whose overexpression in cancer results in shortened patient survival. In this study, we aimed to determine the predictive value of K17 and explore the therapeutic vulnerability in K17‐expressing PDAC, using an unbiased high‐throughput drug screen. Patient‐derived data analysis showed that K17 expression correlates with resistance to gemcitabine (Gem). In multiple in vitro and in vivo models of PDAC, spanning human and murine PDAC cells, and orthotopic xenografts, we determined that the expression of K17 results in a more than twofold increase in resistance to Gem and 5‐fluorouracil, key components of current standard‐of‐care chemotherapeutic regimens. Furthermore, through an unbiased drug screen, we discovered that podophyllotoxin (PPT), a microtubule inhibitor, showed significantly higher sensitivity in K17‐positive compared to K17‐negative PDAC cell lines and animal models. In the clinic, another microtubule inhibitor, paclitaxel (PTX), is used in combination with Gem as a first‐line chemotherapeutic regimen for PDAC. Surprisingly, we found that when combined with Gem, PPT, but not PTX, was synergistic in inhibiting the viability of K17‐expressing PDAC cells. Importantly, in preclinical models, PPT in combination with Gem effectively decreased tumor growth and enhanced the survival of mice bearing K17‐expressing tumors. This provides evidence that PPT and its derivatives could potentially be combined with Gem to enhance treatment efficacy for the ~ 50% of PDACs that express high levels of K17. In summary, we reported that K17 is a novel target for developing a biomarker‐based personalized treatment for PDAC.

Keratin 17 Expression Predicts Poor Clinical Outcome in Patients With Advanced Esophageal Squamous Cell Carcinoma.

The major roles of keratin 17 (K17) as a prognostic biomarker have been highlighted in a range of human malignancies. However, its relevance to esophageal squamous cell carcinoma (ESCC) remains unexplored. In this study, the relationship between K17 expression and clinicopathologic parameters and survival were determined by RNA sequencing (RNA-Seq) in 90 ESCCs and by immunohistochemistry (IHC) in 68 ESCCs. K17 expression was significantly higher in ESCC than in paired normal tissues at both the messenger RNA and protein levels. K17 messenger RNA and staining by IHC were significantly correlated with aggressive characteristics, including advanced clinical stage, invasion depth, and lymph node metastases; and were predictive of poor prognosis in advanced disease patients. Furthermore, K17 expression was detected by IHC in high-grade premalignant lesions of the esophageal mucosa, suggesting that K17 could also be a biomarker of dysplasia of the esophageal mucosa. Overall, this study established that K17 is a negative prognostic biomarker for the most common subtype of esophageal cancer.

Human Hair Outer Root Sheath Cells and Platelet-Lysis Exosomes Promote Hair Inductivity of Dermal Papilla Cell.

Hair loss is a prevalent medical problem in both men and women. Maintaining the potential hair inductivity of dermal papilla cells (DPCs) during cell culture is the main factor in hair follicle morphogenesis and regeneration. The present study was conducted to compare the effects of different concentrations of human hair outer root sheath cell (HHORSC) and platelet lysis (PL) exosomes to maintain hair inductivity of the human dermal papilla cells (hDPCs). In this study, hDPCs and HHORSCs were isolated from healthy hair samples. Specific markers of hDPCs (versican, α-SMA) and HHORSCs (K15) were evaluated using flow cytometric and immunocytochemical techniques. The exosomes were isolated from HHORSCs and PL with ultracentrifugation technique. Western blot was used to detect specific markers of HHORSCs and PL exosomes. Particle size and distribution of the exosomes were analyzed by NanoSight dynamic light NanoSight Dynamic Light Scattering. Different methods such as proliferation test (MTS assay), migration test (Transwell assay) were used to evaluate the effects of different concentrations of exosomes (2,550,100µg/ml) derived from HHORSC and PL on hDPCs. Expression of specific genes in the hair follicle inductivity, including ALP, versican and α-SMA were also evaluated using real time-PCR. The flow cytometry of the specific cytoplasmic markers of the hDPCs and HHORSCs showed expression of versican (77%), α-SMA (55.2%) and K15 (73.2%). The result of particle size and distribution of the exosomes were analyzed by NanoSight dynamic light NanoSight Dynamic Light Scattering, which revealed the majority of HHORSC and PL exosomes were 30-150nm. For 100µg/ml of HHORSC exosomes, the expressions of ALP, versican and α-SMA proteins respectively increased by a factor of 2.1, 1.7and 1.3 compared to those in the control group. In summary, we applied HHORSC exosomes as a new method to support hair inductivity of dermal papilla cells and improve the outcome for the treatment of hair loss.

Keratin expression in gingival tissue and primary cultured gingival keratinocytes: Are there differences?

ObjectiveTo investigate whether the process of primary gingival keratinocytes culture obtained from normal human gingiva modifies the expression of keratins (K) 10, K14, and K19. DesignHuman gingival fragments were collected from healthy individuals in the same oral site. One part of the samples underwent an immunohistochemistry assay for K10, K14, and K19. The labeling in the epithelium was quantified using a semiautomated method. Another part was used for primary gingival keratinocytes isolation and growth in two-dimensional culture. These cells were also stained for K10, K14, and K19 using immunofluorescence and immunocytochemistry. Positive cells were counted, and the nuclei and cytoplasmatic labeling areas were quantified. ResultsIn the gingival tissue, a higher expression was found for K14 versus K10 (p < 0.001); K19 was negative in all samples. In gingival keratinocytes culture, K14 (89.6 %) had the highest expression with significant differences in relation to K10 (76.9 %, p < 0.01) and K19 (9.9 %, p < 0.01). The cells positive for K14 exhibited larger nuclei in comparison with K10 (p < 0.05) and K19 (p < 0.05), suggesting a more undifferentiated phenotype. K19 cells showed the largest cytoplasmatic labeling in relation to K10- (p < 0.05) and K14-positive (p < 0.05) cells. ConclusionThe process of growth in culture of gingival keratinocytes maintained the expression pattern of K10 and K14 observed in gingival tissues. However, this method induces the expression of K19, suggesting a potential transformation of the keratin network presented in the gingival keratinocytes during the formation of a monolayer in vitro. This reflects the dynamics of cell differentiation.

Anti-psoriatic properties of paeoniflorin: suppression of the NF-kappaB pathway and Keratin 17.

Psoriasis is a common inflammatory skin disease characterized by hyperproliferation of epidermal keratinocytes, however, there is still no curative therapy for psoriasis. Paeoniflorin (PF), a Chinese herbal medicine, has shown anti-inflammatory effects. We aimed to illustrate the effect and associated mechanism of PF on keratinocyte proliferation using the IMQ-induced psoriasis mouse model. The anti-psoriatic effect of PF in vivo and in vitro was assessed by western blot, RT-PCR, immunofluorescence, cell counting kit-8 and haematoxylin/eosin staining. In vivo, epidermal thickness, dermal infiltrated lymphocytes and the level of several antimicrobial peptides, pro-inflammatory cytokines, and K17 were significantly reduced in mice with topical application of PF. In vitro, PF inhibited the proliferation of HaCaT cells in a dose-dependent manner, down-regulated K17 expression, and suppressed NF-kappaB activation. Our findings indicate that PF may inhibit the proliferation of keratinocytes by targeting K17, suggesting that PF might be a potential target in the treatment of psoriasis.

Resistin Activates p65 Pathway and Reduces Glycogen Content through Keratin 8

Resistin is associated with metabolic syndrome and inflammatory conditions. Many studies have suggested that resistin inhibits the accumulation of glycogen; however, the exact mechanisms of resistin-induced decrease in glycogen content remain unclear. Keratin 8 is a typical epithelial intermediate filament protein, but numerous studies suggest a vital role of K8 in glucose metabolism. However, it is still not known whether K8 participates in the mediation of resistin-induced reduction of cellular glycogen accumulation. In this study, we found that resistin upregulated expression of the p65 subunit of NF-κB, which led to the promotion of K8 transcriptional expression; in turn, the expression of K8 inhibited glycogen accumulation in HepG2 cells.

Albendazole negatively regulates keratinocyte proliferation.

Increased keratinocyte proliferation occurs in the skin of psoriatic patients and is supposed to play a role in the pathogenesis of this disorder. Compounds interfering with keratinocyte proliferation could be useful in the management of psoriatic patients. To investigate whether albendazole, an anti-helmintic drug that regulates epithelial cell function in various systems, inhibits keratinocyte proliferation in models of psoriasis. Aldara-treated mice received daily topical application of albendazole. Keratinocyte proliferation and keratin (K) 6 and K16 expression were evaluated by immunohistochemistry and Western blotting and inflammatory cells/mediators were analysed by immunohistochemistry and real-time PCR. In human keratinocytes (HEKa and HaCaT) treated with albendazole, cell cycle and proliferation, keratins and cell cycle-associated factors were evaluated by flow cytometry, colorimetric assay and Western blotting respectively. Aldara-treated mice given albendazole exhibited reduced epidermal thickness, decreased number of proliferating keratinocytes and K6/K16 expression. Reduction of CD3- and Ly6G-positive cells in the skin of albendazole-treated mice associated with inhibition of IL-6, TNF-α, IL-1β, IL-17A, IL-36, CCL17, CXCL1, CXCL2 and CXCL5 expression. Treatment of keratinocytes with albendazole reduced K6/K16 expression and reversibly inhibited cell growth by promoting accumulation of cells in S-phase. This phenomenon was accompanied by down-regulation of CDC25A, a phosphatase regulating progression of cell cycle through S-phase, and PKR-dependent hyper-phosphorylation of eIF2α, an inhibitor of CDC25 translation. In Aldara-treated mice, albendazole activated PKR, enhanced eIF2α phosphorylation and reduced CDC25A expression. Data show that albendazole inhibits keratinocyte proliferation and exerts therapeutic effect in a murine model of psoriasis.

The psoriatic shift induced by interleukin 17 is promptly reverted by a specific anti-IL-17A agent in a three-dimensional organotypic model of normal human skin culture.

Interleukin 17A (IL-17A), mainly produced by the T helper subclass Th17, plays a key role in the psoriatic plaque formation and progression. The clinical effectiveness of anti-IL-17A agents is documented, but the early and specific mechanisms of their protection are not identified yet. The challenge of the present study is to investigate the possible reversal exerted by a specific anti-IL-17A agent on the psoriatic events induced by IL-17A in a three-dimensional organotypic model of normal human skin. Bioptic skin fragments obtained after aesthetic surgery of healthy women (n=5) were incubated with i) IL-17A biological inhibitor (anti-IL-17A), ii) IL- 17A, iii) a combination of IL-17A and its specific IL-17A biological inhibitor (COMBO). A Control group was in parallel cultured and incubation lasted for 24 and 48 h epidermal-side-up at the air-liquid interface. All subjects were represented in all experimental groups at all considered time-points. Keratinocyte proliferation and the presence of epidermal Langerhans cells were quantitatively estimated. In parallel with transmission electron microscopy analysis, immunofluorescence studies for the epidermal distribution of keratin (K)10, K14, K16, K17, filaggrin/occludin, Toll-like Receptor 4, and Nuclear Factor kB were performed. IL-17A inhibited cell proliferation and induced K17 expression, while samples incubated with the anti-IL-17A agent were comparable to controls. In the COMBO group the IL-17A-induced effects were almost completely reverted. Our study, for the first time, elucidates the most specific psoriatic cellular events that can be partially affected or completely reverted by a specific anti-IL-17A agent during the early phases of the plaque onset and progression. On the whole, this work contributes to expand the knowledge of the psoriatic tableau.

Keratin 19 Promotes Cell Cycle by Regulating GSK3B‐Cyclin D3 Pathway in Breast Cancer Cells

Keratin 19 (K19) is a cytoskeletal protein that is utilized as a diagnostic and prognostic marker in select human carcinomas. Despite the positive correlation between higher expression of K19 in tumor and worse patient survival, the role of K19 in breast cancer remains unclear. We previously used K19 knockout (KO) MCF7 breast cancer cells to identify that K19 is required for proper cell cycle progression. Specifically, K19 regulated expression of D‐type cyclins (cyclin D1 and cyclin D3) which promote the G1/S transition. We found that K19 interacts with cyclin D3, and a loss of K19 resulted in decreased protein stability of cyclin D3. To better understand how K19 prevents cyclin D3 degradation, we examined the cyclic adenosine 3′,5′‐monophosphate (cAMP) signaling pathway where cAMP induction causes glycogen synthase kinase GSK3B to promote cyclin D3 degradation. When cells were treated with forskolin to elevate intracellular cAMP level, cyclin D3 turnover was increased in the absence of K19, suggesting that K19 inhibits GSK3B from degrading cyclin D3. Indeed, inhibiting GSK3B activity using LiCl and GSK3B expression via siRNA rescued the cyclin D3 level in K19 KO cells. These data suggest that K19 plays an important role in GSK3B‐mediated cyclin D3 degradation. By using molecular biology tools and biochemical approaches, we are in the process of characterizing specifics of K19‐dependent regulation of cyclin D3 stability including identification of GSK3B and K19 domains responsible for their interaction. We aim to provide evidences for a novel mechanism by which a cytoskeletal protein stabilizes a cell cycle regulator and promotes proper cell cycle progression.Schematic model for the role of K19 in regulation of GSK3B‐mediated cyclin D3 degradation.(a) K19 serve as scaffold for both for GSK3B and cyclin D3, preventing GSK3B to access cyclin D3.(b) In absence of K19, GSK3B has a full access to cyclin D3 for degradation.Figure 1

PPAR-α Agonist Fenofibrate Suppressed the Formation of Ocular Surface Squamous Metaplasia Induced by Topical Benzalkonium Chloride.

PurposeTo investigate the effects and mechanisms of the peroxisome proliferator-activated receptor alpha (PPAR-α) agonist fenofibrate on the formation of ocular surface squamous metaplasia induced by topical benzalkonium chloride (BAC) in a mouse model.MethodsOcular surface squamous metaplasia was induced in 16 days by topical BAC application in mice. During the period of induction, mice were divided into four groups: no additional treatment (BAC+UT), topical vehicle (BAC+Vehicle), topical fenofibrate (BAC+Feno), or topical fenofibrate plus intraperitoneal injection of MK886 (BAC+Feno+MK886). The parameters of tear film were evaluated on day 16, and eye specimens were collected. Histologic investigation; PAS assays; immunostaining for cytokeratin 10 (K10), Ki67, and F4/80; and PCR assays for TNF-α and IL-6 were performed. Cell Counting Kit 8 (CCK-8) assays were performed to evaluate the inhibitory effects of fenofibrate on RAW264.7 cells.ResultsFenofibrate suppressed the formation of BAC-induced instable tear film. In the BAC+Feno group, the expression of K10 and Ki67 was lower than in the other three groups. The number of goblet cells was reduced in eyes of the BAC+UT and BAC+Vehicle groups but was maintained in eyes of the BAC+Feno group. The number of F4/80-positive cells and the levels of TNF-α and IL-6 mRNA were significantly reduced in the cornea of the BAC+Feno group. These effects of fenofibrate could be attenuated by MK886. The cell viability of RAW264.7 cells could be significantly inhibited by fenofibrate in a dose-dependent pattern.ConclusionsTopical application of fenofibrate suppressed the formation of ocular surface squamous metaplasia, which might be mediated through the PPAR-α signaling pathway.

Serum lipids, retinoic acid and phenol red differentially regulate expression of keratins K1, K10 and K2 in cultured keratinocytes

Abnormal keratinocyte differentiation is fundamental to pathologies such as skin cancer and mucosal inflammatory diseases. The ability to grow keratinocytes in vitro allows the study of differentiation however any translational value is limited if keratinocytes get altered by the culture method. Although serum lipids (SLPs) and phenol red (PR) are ubiquitous components of culture media their effect on differentiation is largely unknown. We show for the first time that PR and SLP themselves suppress expression of differentiation-specific keratins K1, K10 and K2 in normal human epidermal keratinocytes (NHEK) and two important cell lines, HaCaT and N/TERT-1. Removal of SLP increased expression of K1, K10 and K2 in 2D and 3D cultures, which was further enhanced in the absence of PR. The effect was reversed for K1 and K10 by adding all-trans retinoic acid (ATRA) but increased for K2 in the absence of PR. Furthermore, retinoid regulation of differentiation-specific keratins involves post-transcriptional mechanisms as we show KRT2 mRNA is stabilised whilst KRT1 and KRT10 mRNAs are destabilised in the presence of ATRA. Taken together, our results indicate that the presence of PR and SLP in cell culture media may significantly impact in vitro studies of keratinocyte differentiation.

Long non-coding RNA HUMT hypomethylation promotes lymphangiogenesis and metastasis via activating FOXK1 transcription in triple-negative breast cancer

BackgroundTriple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer with highly invasive ability and metastatic nature to the lymph nodes. Long non-coding RNAs (lncRNAs) have been widely explored in cancer tumorigenesis and progression. However, their roles in TNBC lymph node metastasis remains rarely studied.MethodsThe expression of lncRNA highly upregulated in metastatic TNBC (HUMT) in cell lines and tissues was detected by quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH). RNA immunoprecipitation (RIP) and RNA pulldown were used to verify the interaction between lncRNA and protein. Chromatin immunoprecipitation (CHIP) and dCas9-gRNA-guided chromatin immunoprecipitation (dCas9-CHIP) were conducted to identify the specific binding site of HUMT-YBX1 complex. Western blot was used to detect the downstream of HUMT.ResultsHUMT was significantly upregulated in lymph node invasive cells and predicted poorer clinical prognosis. Functional study indicated that HUMT promoted lymphangiogenesis and lymph node metastasis. Bioinformatic analysis and qRT-PCR showed that the high expression of HUMT was correlated with the hypomethylation status of its promoter region. Further, HUMT recruited Y-box binding protein 1 (YBX1) to form a novel transcription complex and activated the expression of forkhead box k1 (FOXK1), thus enhancing the expression of vascular endothelial growth factor C (VEGFC). The therapeutic value was further validated in patient-derived xenograft (PDX) models, and a combined marker panel exhibited a better prognostic value for TNBC in receiver operating characteristic (ROC) analysis.ConclusionsOur study identified a novel TNBC lymph node metastasis-associated lncRNA, which promoted TNBC progression and indicated a novel biomarker and potential therapeutic target for TNBC lymph node metastasis.

Ichthyosis with confetti caused by new and recurrent mutations in KRT10 associated with varying degrees of keratin 10 mis-localization

BackgroundIchthyosis with confetti (IWC) is an extremely rare autosomal-dominant genodermatosis characterized by erythroderma with numerous confetti-like pale spots. IWC is caused by mutations in KRT10 (IWC-I) or KRT1 (IWC-II) which affect their tail domains. In IWC-I, the mutations lead to replacement of glycine/serine-rich keratin 10 (K10) tail with arginine- or alanine-rich frameshift motifs, causing K10 mis-localization which might trigger loss of the mutant KRT10 allele via mitotic recombination, leading to genetic reversion. ObjectiveTo investigate mutations in five IWC-I patients and their functional consequences. MethodsWe performed Sanger sequencing of KRT1 and KRT10 in peripheral blood samples of five patients, with highly polymorphic KRT10 SNPs genotyped to confirm loss-of-heterozygosity in the epidermis of pale spots. K10 expression pattern was examined in both patient skin biopsies and HaCaT cells overexpressing mutant KRT10-enhanced green fluorescence protein fusion. ResultsFour novel and one recurrent KRT10 mutations were identified in patient peripheral blood samples but not in the corresponding pale spot epidermis. Two of the mutations, c.1696_1699dupCACA and c.1676dupG, affected residues close to K10 carboxyl terminus and encoded only 3 and 6 arginine residues, which were far fewer than reported previously. Interestingly, imaging analyses for K10 in HaCaT cells overexpressing either of these two mutations and in the corresponding patients' affected skin, showed a remarkably lower level of K10 mis-localization compared to that of other mutations reported in this study. ConclusionsOur findings suggest that the number of arginine residues in the mutant tail may correlate with the level of K10 mis-localization in IWC-I keratinocytes. These results expand the genotypic and phenotypic spectrum of IWC-I.

Trimethylchlorosilane, (CH3)3SiCl: OH reaction kinetics and infrared spectrum

AbstractRate coefficients for the OH + (CH3)3SiCl (trimethylchlorosilane) gas‐phase reaction were measured over the temperature range 295–375 K using a pulsed laser photolysis laser‐induced fluorescence technique. The room temperature rate coefficient was determined to be k1(295 K) = (2.51 ± 0.13) × 10−13 cm3 molecule–1 s–1. The Arrhenius expression k1(T) = (7.06 ± 2.15) × 10−12 exp[–(992 ± 101)/T] cm3 molecule–1 s–1, where the quoted uncertainties are 2σ fit precision, describes the measured temperature dependence very well. As part of this work, the infrared spectra of CH3)3SiCl was measured.

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube.

Understanding the mechanism of high-temperature reactions of aromatic hydrocarbons and radicals is essential for the modeling of hydrocarbon growth processes in combustion environments. In this study, the thermal decomposition reaction of benzyl radicals was investigated using time-resolved broadband cavity-enhanced absorption spectroscopy behind reflected shock waves at a postshock pressure of 100 kPa and temperatures of 1530, 1630, and 1740 K. The transient absorption spectra during the decomposition were recorded over the spectral range of 282-410 nm. The spectra were contributed by the absorption of benzyl radicals and some transient and residual absorbing species. The temporal behavior of the absorption was analyzed using a kinetic model to determine the rate constant for benzyl decomposition. The obtained rate constants can be represented by the Arrhenius expression k1 = 1.1 × 1012 exp(-30 500 K/T) s-1 with an estimated logarithmic uncertainty of Δlog10 k = ±0.2. Kinetic simulation of the secondary reactions indicated that fulvenallenyl radicals are potentially responsible for the transient absorption that appeared around 400 nm. This assignment is consistent with the available spectroscopic information of this radical. Possible candidates for the residual absorbing species are presented, suggesting the potential importance of ortho-benzyne as a reactive intermediate.

Epidermal ROCK2 induces AKT1/GSK3β/β-catenin, NFκB and dermal tenascin C; but enhanced differentiation and p53/p21 inhibit papilloma

ROCK2 roles in epidermal differentiation and carcinogenesis have been investigated in mice expressing an RU486-inducible, 4HT-activated ROCK2 transgene (K14.creP/lslROCKer). RU486/4HT-mediated ROCKer activation induced epidermal hyperplasia similar to cutaneous oncogenic rasHa (HK1.ras); however ROCKer did not elicit papillomas. Instead, anomalous basal-layer ROCKer expression corrupted normal ROCK2 roles underlying epidermal rigidity/stiffness and barrier maintanance, resulting in premature keratin K1, loricrin and filaggrin expression. Also, hyperproliferative/stress-associated keratin K6 was reduced; possibly reflecting altered ROCK2 roles in epidermal rigidity and keratinocyte flexibility/migration during wound healing. Consistent with increased proliferation, K14.creP/lslROCKer hyperplasia displayed supra-basal-to-basal increases in activated p-AKT1, inactivated p-GSK3β ser9 and membranous/nuclear β-catenin expression together with weak NFκB, which were absent in equivalent HK1.ras hyperplasia. Furthermore, ROCKer-mediated increases in epidermal rigidity via p-MypT1 inactivation/elevated MLC, coupled to anomalous β-catenin expression, induced tenascin C-positive dermal fibroblasts. Alongside an altered ECM, these latent tenascin C-positive dermal fibroblasts may become putative pre-cancer-associated fibroblasts (pre-CAFs) and establish a susceptibility that subsequently contributes to tumour progression. However, anomalous differentiation was also accompanied by an immediate increase in basal-layer p53/p21 expression; suggesting that while ROCK2/AKT1/β-catenin activation increased keratinocyte proliferation resulting in hyperplasia, compensatory p53/p21 and accelerated differentiation helped inhibit papillomatogenesis.

Aurora-A/SOX8/FOXK1 signaling axis promotes chemoresistance via suppression of cell senescence and induction of glucose metabolism in ovarian cancer organoids and cells.

Rationale: Cisplatin derivatives are first-line chemotherapeutic agents for epithelial ovarian cancer. However, chemoresistance remains a major hurdle for successful therapy and the underlying molecular mechanisms are poorly understood at present.Methods: RNA sequencing of organoids (PDO) established from cisplatin-sensitive and -resistant ovarian cancer tissue samples was performed. Glucose metabolism, cell senescence, and chemosensitivity properties were subsequently examined. Immunoprecipitation, mass spectrometry, Fӧrster resonance energy transfer-fluorescence lifetime imaging (FRET-FLIM), luciferase reporter assay, ChIP and animal experiments were conducted to gain insights into the specific functions and mechanisms of action of the serine/threonine kinase, Aurora-A, in ovarian cancer.Results: Aurora-A levels were significantly enhanced in cisplatin-resistant PDO. Furthermore, Aurora-A promoted chemoresistance through suppression of cell senescence and induction of glucose metabolism in ovarian cancer organoids and cells. Mechanistically, Aurora-A bound directly to the transcription factor sex determining region Y-box 8 (SOX8) and phosphorylated the Ser327 site, in turn, regulating genes related to cell senescence and glycolysis, including hTERT, P16, LDHA and HK2, through enhancement of forkhead-box k1 (FOXK1) expression.Conclusions: Aurora-A regulates cell senescence and glucose metabolism to induce cisplatin resistance by participating in the SOX8/FOXK1 signaling axis in ovarian cancer. Our collective findings highlight a novel mechanism of cisplatin resistance and present potential therapeutic targets to overcome chemoresistance in ovarian cancer.

Tissue engineering of a tympanic membrane graft using decellularized nasal septal mucosa seeded with tragus chondrocytes: a morphological In vitro study

Objective: Tympanic membrane (TM) perforations require surgical repair with graft constituents. Tissue engineering which used cells, scaffold materials, and bioactive molecules facilitates an opportunity in otology for the synthesis of an ideal TM graft having proper mechanical possessions and high acoustic properties. The purpose of this study was to analyze the efficacy and feasibility of decellularized nasal septal mucosa (DNSM) seeded with tragus chondrocytes for in vitro regeneration of a TM graft material. Methods: A NSM scaffold constructed with decellularization was seeded with flow cytometry-characterized tragus chondrocytes. Cells were grown on NSM scaffold to produce an “artificial TM graft” (ATMG). Sections of untreated NSM (UNSM), DNSM, and ATMG were compared by histological examinations and immunohistochemistry analysis (i.e., total oxidant status [TOS] assay, cytokeratin K15 expression, Bcl-2, and tumour necrosis factor-alpha TNF-α). Results: Histological analysis of DNSM seeded with chondrocytes indicated a healthy tissue formation suggesting that a cytocompatible ATMG was produced artificially. When compared with UNSM and DNSM, low TOS level, high cytokeratin K15 expression, high Bcl-2, and acceptable TNF-α levels in ATMG samples indicated the presence of healthy chondrocytes and their proper integration to the scaffold with low risk of apoptosis. Conclusion: This study is a prospective investigation for ATMG engineering based on the patient's own tragal chondrocytes seeded over DNSM scaffold, the employed biological niche. The aim of supplementing an ATMG to the armamentarium of graft alternatives will lead to a significant potential for surgical convenience in otology.

OH* chemiluminescence in the H2[sbnd]NO2 and H2[sbnd]N2O systems

Shock-tube experiments were performed in a mixture of 0.222% H2/0.392% NO2/Ar between 1535 and 2003 K near 1.1 atm. Time histories of OH* chemiluminescence from the A→X band near 307 nm were recorded and showed poor agreement with predictions from a recent hydrocarbon/NOx model when only the OH*-forming reactions N2O + H ⇆ N2 + OH* (R2) and O + H (+M) ⇆ OH* (+M) (R3) were included. Since chemiluminescence is strongly correlated with heat release and since the reaction NO2 + H ⇆ NO+OH is known to be primarily responsible for heat release during H2NO2 oxidation, the chemiluminescent reactionNO2 + H ⇆ NO + OH* (R1)was proposed for the first time. By fitting the experimental OH* data, a best-fit rate constant was obtained as k1=7.0×1013exp(−27,680/T), with k1 in cm3 mol−1 s−1 and T in K. This expression for k1 is valid in the experimental temperature range of 1535 to 2003 K. The fitted k1 value is dependent on the base NOx mechanism used. OH* profiles were also acquired in a mixture of 0.333% H2/0.666% N2O/Ar between 1448 and 1776 K near 1.1 atm. The introduction of the new reaction R1 into the mechanism had no effect on the modeling of either the newly acquired H2N2O OH* data or previous H2N2O OH* data from the literature. Finally, R1 and R2 violate a long-held assumption concerning the exothermicity of such reactions, suggesting that the exothermicity criteria used to evaluate potential chemiluminescent reactions could be relaxed in future studies. Instead, a new methodology based on both the enthalpy of reaction and the entropy of reaction could be employed to identify new chemiluminescent reactions. To the best of the authors’ knowledge, this is the first detailed study of OH* chemiluminescence kinetics in the H2NO2 system.