HIF-1α repairs degenerative chondrocyte glycolytic metabolism by the transcriptional regulation of Runx2.

OBJECTIVE: HIF-1α and Runx2 expression usually increase in chondrocytes (CHs) during osteoarthritis (OA), which involves the changes in glycolytic metabolism. However, the molecular regulation of HIF-1α related to the CHs glycolytic metabolism is still unclear. In this study, we aimed to reveal the mediation of HIF-1α by Runx2 and its effect on the glycolytic metabolism of degenerative CHs. PATIENTS AND METHODS: The expression of HIF-1α, Runx2, and the degenerative markers of CHs in both natural conditions from the OA patients and IL-1ß treated in vitro model was analyzed by a Western blot or real-time polymerase chain reaction (RT-PCR). The glycolytic metabolism was determined by the intracellular glucose uptake and adenosine triphosphate (ATP) generation. Transfection of siRNA coding HIF-1α or Runx2 was used to clear the function between HIF-1α and Runx2 in the glycolytic metabolism of degenerated CHs caused by IL-1ß. Chromatin immunoprecipitation (ChIP) and Luciferase reporter gene assay were used to verify the Runx2 protein binds to the promoter of HIF-1α and promote its expression. RESULTS: HIF-1α and Runx2 were increased, and glucose uptake and ATP generation were decreased in the degenerative CHs from both OA and IL-1ß conditions. Under the stimulation of IL-1ß, Runx2 silencing rejected the upregulation of HIF-1α and further aggravated the glycolytic metabolism. When HIF-1α was silenced, the glycolytic metabolism of CHs was also suppressed. Besides, Runx2 protein could regulate HIF-1α expression in the transcriptional level by binding to its promoter. CONCLUSIONS: OHIF-1α plays a role in the self-repair of the glycolytic metabolism of degenerative CHs via the transcriptional regulation of Runx2.

Electrospun composite nanofibre fabrics containing green reduced Ag nanoparticles as an innovative type of antimicrobial insole.

In this study, polyvinyl alcohol (PVA) nanofibrous membranes containing silver nanoparticles (Ag NPs) were successfully fabricated by the combination of electrospinning and a green reduction approach. Through the electrospinning technique, uniform and smooth nanofibres can be obtained, and the Ag NPs with a narrow size distributions are well dispersed in PVA nanofibres. The investigation indicates that the mass ratio of reductant tea polyphenols and AgNO3 play a crucial role in controlling the size of the Ag NPs. More importantly, multi-layered fabrics with a layer of PVA/Ag NP nanofibrous membrane layered onto cotton substrates were developed and applied to shoe insoles. The fabricated shoe insoles with functionalized PVA nanofibres exhibit remarkable antimicrobial activity against both E. coli and S. aureus (i.e. antibacterial rate > 99%). The creation of such an encouraging fabric could establish a new optimization methodology for producing nanoengineered functional textiles.

KEAP1/NRF2 signaling pathway mutations in cervical cancer.

OBJECTIVE: The aim of the present study was to explore the potential involvement of mutations in the KEAP1/NRF2 signaling pathway in Chinese samples with cervical cancer. PATIENTS AND METHODS: 236 Chinese patients with various types of cervical cancer were recruited, and the coding exons and the corresponding intron-exon boundaries of the KEAP1 and NRF2 genes were analyzed for the potential mutations in the KEAP1/NRF2 signaling pathway. RESULTS: A novel KEAP1 missense somatic mutation (c.1408C>T, p.R470C) and 5 NRF2 missense somatic mutations (c.72G>C, p.W24C; c.85G>T, p.D29Y; c.101G>A, p.R34Q; c.230A>C, p.D77A and c.242G>A p.G81D) were identified in 187 patients with cervical squamous cell carcinoma, respectively; no mutations were detected in other subtypes. All these mutations were heterozygous and predicted to be pathogenic by PolyPhen-2, MutationTaster programs, and evolutionary conservation analysis. Among these mutations, the KEAP1 (p.R470C) and 3 NRF2 mutations (p.D29Y, p.D77A, and p.G81D) were detected in cervical cancer for the first time. Also, no mutations were identified in our 21 adenosquamous carcinomas or 25 adenocarcinomas. CONCLUSIONS: We identified 6 potential diseases causing mutations in the KEAP1/NRF2 signaling pathway in 187 (3.2%) Chinese cases with cervical squamous cell carcinoma, implicating KEAP1/NRF2 signaling pathway might play an active role in the pathogenesis of this subtype of cervical cancer. Furthermore, among these detected mutations, the KEAP1 and 3 NRF2 mutations were reported in cervical cancer for the first time.

Appropriate dose of Lactobacillus buchneri supplement improves intestinal microbiota and prevents diarrhoea in weaning Rex rabbits.

This study examined the effects on intestinal microbiota and diarrhoea of Lactobacillus buchneri supplementation to the diet of weaning Rex rabbits. To this end, rabbits were treated with L. buchneri at two different doses (LC: 104 cfu/g diet and HC: 105 cfu/g diet) for 4 weeks. PCR-DGGE was used to determine the diversity of the intestinal microbiota, while real-time PCR permitted the detection of individual bacterial species. ELISA and real-time PCR allowed the identification of numerous cytokines in the intestinal tissues. Zonula occludens-1, polymeric immunoglobulin receptor and immunoglobulin A genes were examined to evaluate intestinal barriers. Results showed that the biodiversity of the intestinal microbiota of weaning Rex rabbits improved in the whole tract of the treated groups. The abundance of most detected bacterial species was highly increased in the duodenum, jejunum and ileum after L. buchneri administration. The species abundance in the HC group was more increased than in the LC group when compared to the control. Although the abundance of Enterobacteriaceae exhibited a different pattern, Escherichia coli was inhibited in all treatment groups. Toll-like receptor (TLR)2 and TLR4 genes were down-regulated in all intestinal tissues as the microbiota changed. In the LC group, the secretion of the inflammatory cytokine tumour necrosis factor-α was reduced, the gene expression of the anti-inflammatory cytokine interleukin (IL)-4 was up-regulated and the expression of intestinal-barrier-related genes was enhanced. Conversely, IL-4 expression was increased and the expression of other tested genes did not change in the HC group. The beneficial effects of LC were greater than those of HC or the control in terms of improving the daily weight gain and survival rate of weaning Rex rabbits and reducing their diarrhoea rate. Therefore, 104 cfu/g L. buchneri treatment improved the microbiota of weaning Rex rabbits and prevented diarrhoea in these animals.

[Cancer-associated-fibroblasts regulate the chemoresistance of lung cancer cell line A549 via SDF-1 secretion].

Objective: To investigate whether cancer-associated- fibroblasts (CAF), the key component of tumor microenvironment, regulate the chemoresistant capacity of lung cancer cell line A549 through SDF-1 secretion. Methods: Primary cell isolation techniques was used to isolate cancer-associated-fibroblasts from lung cancer patients. MTT assay was applied to determine the proliferation and chemoresistance of A549 cells. Quantative PCR was used to detect the mRNA changes of Bcl-xL. Western blotting was used to detect the protein expression of Bcl-xL. ELISA was applied to detect the SDF-1 secretion from normal fibroblasts (NF) and CAF. Results: CAF promoted the proliferation of A549 cells, while NF had no significant effect on them. After 72 hrs incubation, the absorbance value of A549+ CAF medium group was 0.814±0.006, significantly different from the 0.753±0.006 of the A549+ NF medium group (P<0.05). The Q-PCR assay indicated that mRNA expressions of Bcl-xL in the A549 group, A549+ NF medium group and A549+ CAF medium group were 1.00±0.11, 1.10±0.09 and 3.50±0.30, respectively, showing a significant difference between the A549+ NF medium group and A549+ CAF medium group (P<0.05). The Western blot showed that protein expressions of Bcl-xL in the A549 group, A549+ NF medium group and A549+ CAF medium group were 1.00±0.08, 1.10±0.12 and 3.10±0.25, respectively, with a significant difference between the A549+ NF medium group and A549+ CAF medium group (P<0.05). The ELISA results showed that the SDF-1 concentrations in the A549+ NF medium group and A549+ CAF medium group were 3.23±0.02 and 9.53±0.10, respectively, significantly different from each other (P<0.05). The MTT assay indicated that the absorbance values of OD of A549 group, A549+ AMD3100 group, A549+ NF medium group, A549+ NF medium+ AMD3100 group, A549+ CAF medium and A549+ CA Fmedium+ AMD3100 group were 0.43±0.03, 0.25±0.02, 0.48±0.03, 0.31±0.03, 0.72±0.06 and 0.45±0.03, respectively. The data of A549+ NF medium group was significantly different from that of A549+ CAF medium group (P<0.05). Conclusions: Cancer-associated-fibroblasts enhance the drug resistance of A549 cells through SDF-1 secretion, upregulating the expression level of Bcl-xL through interaction with CXCR4. Our study not only illustrates that tumor microenvironment is able to enhance drug resistance of tumor, but also provides experimental evidence for the cancer-associated-fibroblasts as a potential therapeutic target for the treatment of lung cancer.

Blockade of ß-catenin signaling attenuates toluene diisocyanate-induced experimental asthma.

BACKGROUND: Aberrant activation of ß-catenin signaling by both WNT-dependent and WNT-independent pathways has been demonstrated in asthmatic airways, which is thought to contribute critically in remodeling of the airways. Yet, the exact role of ß-catenin in asthma is very poorly defined. As we have previously reported abnormal expression of ß-catenin in a toluene diisocyanate (TDI)-induced asthma model, in this study, we evaluated the therapeutic efficacy of two small molecules XAV-939 and ICG-001 in TDI-asthmatic male BALB/c mice, which selectively block ß-catenin-mediated transcription. METHODS: Male BALB/c mice were sensitized and challenged with TDI to generate a chemically induced asthma model. Inhibitors of ß-catenin, XAV-939, and ICG-001 were respectively given to the mice through intraperitoneally injection. RESULTS: TDI exposure led to a significantly increased activity of ß-catenin, which was then confirmed by a luciferase assay in 16HBE transfected with the TOPFlash reporter plasmid. Treatment with either XAV-939 or ICG-001 effectively inhibited activation of ß-catenin and downregulated mRNA expression of ß-catenin-targeted genes in TDI-asthmatic mice, paralleled by dramatically attenuated TDI-induced hyperresponsiveness and inflammation of the airway, alleviated airway goblet cell metaplasia and collagen deposition, decreased Th2 inflammation, as well as lower levels of TGFß1, VEGF, HMGB1, and IL-1ß. CONCLUSION: The results showed that ß-catenin is a principal mediator of TDI-induced asthma, proposing ß-catenin as a promising therapeutic target in asthma.

FBW7 mutations mediate resistance of colorectal cancer to targeted therapies by blocking Mcl-1 degradation.

Colorectal cancer (CRC), the second leading cause of cancer-related deaths in the US, has been treated with targeted therapies. However, the mechanisms of differential responses and resistance of CRCs to targeted therapies are not well understood. In this study, we found that genetic alterations of FBW7, an E3 ubiquitin ligase and a tumor suppressor frequently mutated in CRCs, contribute to resistance to targeted therapies. CRC cells containing FBW7-inactivating mutations are insensitive to clinically used multi-kinase inhibitors of RAS/RAF/MEK/ERK signaling, including regorafenib and sorafenib. In contrast, sensitivity to these agents is not affected by oncogenic mutations in KRAS, BRAF, PIK3CA or p53. These cells are defective in apoptosis owing to blocked degradation of Mcl-1, a pro-survival Bcl-2 family protein. Deleting FBW7 in FBW7-wild-type CRC cells abolishes Mcl-1 degradation and recapitulates the in vitro and in vivo drug-resistance phenotypes of FBW7-mutant cells. CRC cells selected for regorafenib resistance have progressive enrichment of pre-existing FBW7 hotspot mutations, and are cross-resistant to other targeted drugs that induce Mcl-1 degradation. Furthermore, a selective Mcl-1 inhibitor restores regorafenib sensitivity in CRC cells with intrinsic or acquired resistance. Together, our results demonstrate FBW7 mutational status as a key genetic determinant of CRC response to targeted therapies, and Mcl-1 as an attractive therapeutic target.

[Investigation of CXCR4 mediated chemoresistance in nasopharyngeal carcinoma cell line CNE2].

Objective:Since nasopharyngeal carcinoma is easy to develop resistance during cisplatin-based chemotherapy,CXCR4 expression levels were elevated in mang tumors,and the factor to do with tumor metastasis and chemotherapy drug resistance,and so on has a very important link.We established cisplatin-resistant nasopharyngeal carcinoma cell line, named as CNE2/DDP, and investigated the function of CXCR4 in molecular mechanism behind this resistance.Method:CNE2/DDP was firstly build up by increasing concentration of cisplatin. And then afterwards,MTT assay, RNA interference techniques, microRNA overexpresion techniques, quantative PCR and western blotting were applied to analyze the function of CXCR4 and its downstream effectors.Result:①the expression of CXCR4 was increased in CNE2/DDP and downregulation of CXCR4 with CXCR4 siRNA was able to decrease the resistance of CNE/DDP to cisplatin; ②the expression of let-7a was decrease in CNE2/DDP, while the expression of bcl-2 was increased. Upregulation of let-7a via transfection of let-7a mimics could downregulate the expression of bcl-2 and damage the resistance of CNE2/DDP to cisplation;③downregulation of CXCR4 through CXCR4 siRNA transfection was capable of improving the expression of let-7a. Conclusion:We were the first to found that CXCR4 was related to chemoresistance of CNE2/DPP to cisplatin. Meanwhile, we confirmed that CXCR4 affected the expression of bcl-2 through regulating the expression of let-7a to modulate the chemoresistance of CNE2/DPP to cisplatin.

Discovery of a BTK/MNK dual inhibitor for lymphoma and leukemia.

Bruton's tyrosine kinase (BTK) kinase is a member of the TEC kinase family and is a key regulator of the B-cell receptor (BCR)-mediated signaling pathway. It is important for B-cell maturation, proliferation, survival and metastasis. Pharmacological inhibition of BTK is clinically effective against a variety of B-cell malignances, such as mantle cell lymphoma, chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML) and activated B-cell-diffuse large B-cell lymphoma. MNK kinase is one of the key downstream regulators in the RAF-MEK-ERK signaling pathway and controls protein synthesis via regulating the activity of eIF4E. Inhibition of MNK activity has been observed to moderately inhibit the proliferation of AML cells. Through a structure-based drug-design approach, we have discovered a selective and potent BTK/MNK dual kinase inhibitor (QL-X-138), which exhibits covalent binding to BTK and noncovalent binding to MNK. Compared with the BTK kinase inhibitor (PCI-32765) and the MNK kinase inhibitor (cercosporamide), QL-X-138 enhanced the antiproliferative efficacies in vitro against a variety of B-cell cancer cell lines, as well as AML and CLL primary patient cells, which respond moderately to BTK inhibitor in vitro. The agent can effectively arrest the growth of lymphoma and leukemia cells at the G0-G1 stage and can induce strong apoptotic cell death. These primary results demonstrate that simultaneous inhibition of BTK and MNK kinase activity might be a new therapeutic strategy for B-cell malignances.

Gene expression in major depressive disorder.

The search for genetic variants underlying major depressive disorder (MDD) has not yet provided firm leads to its underlying molecular biology. A complementary approach is to study gene expression in relation to MDD. We measured gene expression in peripheral blood from 1848 subjects from The Netherlands Study of Depression and Anxiety. Subjects were divided into current MDD (N=882), remitted MDD (N=635) and control (N=331) groups. MDD status and gene expression were measured again 2 years later in 414 subjects. The strongest gene expression differences were between the current MDD and control groups (129 genes at false-discovery rate, FDR<0.1). Gene expression differences across MDD status were largely unrelated to antidepressant use, inflammatory status and blood cell counts. Genes associated with MDD were enriched for interleukin-6 (IL-6)-signaling and natural killer (NK) cell pathways. We identified 13 gene expression clusters with specific clusters enriched for genes involved in NK cell activation (downregulated in current MDD, FDR=5.8 × 10(-5)) and IL-6 pathways (upregulated in current MDD, FDR=3.2 × 10(-3)). Longitudinal analyses largely confirmed results observed in the cross-sectional data. Comparisons of gene expression results to the Psychiatric Genomics Consortium (PGC) MDD genome-wide association study results revealed overlap with DVL3. In conclusion, multiple gene expression associations with MDD were identified and suggest a measurable impact of current MDD state on gene expression. Identified genes and gene clusters are enriched with immune pathways previously associated with the etiology of MDD, in line with the immune suppression and immune activation hypothesis of MDD.

Loss of caspase-3 sensitizes colon cancer cells to genotoxic stress via RIP1-dependent necrosis.

Caspase-3 is the best known executioner caspase in apoptosis. We generated caspase-3 knockout (C3KO) and knockdown human colorectal cancer cells, and found that they are unexpectedly sensitized to DNA-damaging agents including 5-fluorouracil (5-FU), etoposide, and camptothecin. C3KO xenograft tumors also displayed enhanced therapeutic response and cell death to 5-FU. C3KO cells showed intact apoptosis and activation of caspase-7 and -9, impaired processing of caspase-8, and induction of necrosis in response to DNA-damaging agents. This form of necrosis is associated with HMGB1 release and ROS production, and suppressed by genetic or pharmacological inhibition of RIP1, MLKL1, or caspase-8, but not inhibitors of pan-caspases or RIP3. 5-FU treatment led to the formation of a z-VAD-resistant pro-caspase-8/RIP1/FADD complex, which was strongly stabilized by caspase-3 KO. These data demonstrate a key role of caspase-3 in caspase-8 processing and suppression of DNA damage-induced necrosis, and provide a potentially novel way to chemosensitize cancer cells.

Targeting Bax interaction sites reveals that only homo-oligomerization sites are essential for its activation.

Bax is a proapoptotic Bcl-2 family member that has a central role in the initiation of mitochondria-dependent apoptosis. However, the mechanism of Bax activation during apoptosis remains unsettled. It is believed that the activation of Bax is mediated by either dissociation from prosurvival Bcl-2 family members, or direct association with BH3-only members. Several interaction sites on Bax that mediate its interactions with other Bcl-2 family members, as well as its proapoptotic activity, have been identified in previous studies by other groups. To rigorously investigate the functional role of these interaction sites, we knocked in their respective mutants using HCT116 colon cancer cells, in which apoptosis induced by several stimuli is strictly Bax-dependent. Bax-mediated apoptosis was intact upon knock-in (KI) of K21E and D33A, which were shown to block the interaction of Bax with BH3-only activators. Apoptosis was partially reduced by KI of D68R, which impairs the interaction of Bax with prosurvival members, and S184V, a constitutively mitochondria-targeting mutant. In contrast, apoptosis was largely suppressed by KI of L70A/D71A, which blocks homo-oligomerization of Bax and its binding to prosurvival Bcl-2 family proteins. Collectively, our results suggest that the activation of endogenous Bax in HCT116 cells is dependent on its homo-oligomerization sites, but not those previously shown to interact with BH3-only activators or prosurvival proteins only. We therefore postulate that critical interaction sites yet to be identified, or mechanisms other than protein-protein interactions, need to be pursued to delineate the mechanism of Bax activation during apoptosis.

Inhibition of sphingosine kinase 1 suppresses proliferation of glioma cells under hypoxia by attenuating activity of extracellular signal-regulated kinase.

OBJECTIVES: Sphingosine kinase (SphK), which is regulated by hypoxia, catalyses phosphorylation of sphingosine to produce sphingosine-1-phosphate, which stimulates invasiveness of gliomas. However, whether SphK is involved in proliferation of glioma cells under hypoxic conditions is not clearly understood. In this study, we have investigated the role of SphK in of proliferation glioma cells under hypoxia. MATERIALS AND METHODS: Effects of small interfering RNA (siRNA) on SphKs, SKI (inhibitor of SphK) and U0126 (inhibitor of ERK) on proliferation of glioma cells under hypoxia were studied using CCK-8 assay and flow cytometry. Protein expression profiles were evaluated by Western blot analysis. RESULTS: SKI suppressed proliferation of glioma cells under hypoxia. Similarly, downregulation of SphKs by siRNA inhibited glioma cell proliferation, and the cell cycle was arrested in G(2) /M phase when SphK1 was inhibited. In addition, inhibition of SphK1 attenuated phosphorylation of ERK in hypoxic conditions. Furthermore, U0126 markedly inhibited cell population growth and arrested cells in G(2) /M as effectively as SKI. However, silencing SphK2 induced cell cycle arrest in the S phase and it showed little effect on hypoxia-induced activation of ERK. CONCLUSIONS: SphK1 and SphK2 are involved in proliferation of glioma cells in hypoxic conditions through distinct signalling pathways. SphK1, but not SphK2, promotes cell population expansion in hypoxic conditions by activating ERK.

Understanding the population structure of North American patients with cystic fibrosis.

It is generally presumed that the cystic fibrosis (CF) population is relatively homogeneous, and predominantly of European origin. The complex ethnic make-up observed in the CF patients collected by the North American CF Modifier Gene Consortium has brought this assumption into question, and suggested the potential for population substructure in the three CF study samples collected from North America. It is well appreciated that population substructure can result in spurious genetic associations. To understand the ethnic composition of the North American CF population, and to assess the need for population structure adjustment in genetic association studies with North American CF patients, genome-wide single-nucleotide polymorphisms on 3076 unrelated North American CF patients were used to perform population structure analyses. We compared self-reported ethnicity to genotype-inferred ancestry, and also examined whether geographic distribution and cystic fibrosis transmembrane regulator (CFTR) mutation type could explain the population structure observed. Although largely Caucasian, our analyses identified a considerable number of CF patients with admixed African-Caucasian, Mexican-Caucasian and Indian-Caucasian ancestries. Population substructure was present and comparable across the three studies of the consortium. Neither geographic distribution nor CFTR mutation type explained the population structure. Given the ethnic diversity of the North American CF population, it is essential to carefully detect, estimate and adjust for population substructure to guard against potential spurious findings in CF genetic association studies. Other Mendelian diseases that are presumed to predominantly affect single ethnic groups may also benefit from careful analysis of population structure.

Molluscicidal activity of the plant Eupatorium adenophorum against Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum.

The potential molluscicidal activities of aqueous extracts of Eupatorium adenophorum have recently been evaluated against Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum. The snails were continuously exposed to extracts of the leaves, roots or stems [each at concentrations of 0.27%, 0.50% and 0.86% (w/v)], with survival recorded 6, 12, 24, 30, 36, 48, 52, 58, 70, 76, 82 and 96 h after the start of the exposure. Even at the lowest concentration tested (0.27%), the leaf extract caused mortality in excess of 50% after 58 h and 100% mortality after 82 h. This extract was significantly more effective against O. hupensis than the stem or root extract (P<0.05) but there was no statistically significant difference between the root and stem extracts in their molluscicidal effects (P>0.05). These preliminary results indicate that E. adenophorum may potentially provide a new molluscicide that could give effective and environmentally-friendly control of schistosomiasis in humans and livestock. The toxicity of E. adenophorum extracts, or molluscicidal compounds isolated from such extracts, to other snail hosts of human parasites and to non-target species of aquatic life will be investigated.

Toluene diisocyanate enhances human bronchial epithelial cells' permeability partly through the vascular endothelial growth factor pathway.

BACKGROUND: Toluene diisocyanate (TDI) is a recognized chemical asthmogen; yet, the mechanisms of its toxicity have not been elucidated. OBJECTIVE: To investigate the influence of TDI on the permeability of human bronchial epithelial cell (HBE; HBE135-E6E7) monolayers in vitro, and the expression of vascular endothelial growth factor (VEGF) in these cells. METHODS: TDI-human serum albumin (HSA) conjugates were prepared by a modification of Son's method. Fluorescein isothiocyanate-labelled dextran and transmission electron microscopy were used to evaluate the effects of TDI-HSA on HBE135-E6E7 permeability. RT-PCR and ELISA were used to evaluate VEGF gene expression and protein release from HBE135-E6E7 cells stimulated by TDI-HSA. A VEGF-neutralizing antibody was used in monolayer permeability experiments to determine the role of the VEGF pathway in this process. RESULTS: TDI-HSA significantly increased the permeability coefficients of HBE135-E6E7 monolayers (P<0.01). TDI-HSA treatment significantly increased the expression of VEGF165 and VEGF189 genes (P<0.01). ELISA showed that TDI significantly induces VEGF release from HBE135-E6E7 cells. Cells treated with TDI-HSA and VEGF-neutralizing antibody had significantly lower permeability coefficients than cells treated with TDI-HSA only (P<0.01), but still significantly higher than control cells (P<0.01). Cells treated with TDI-HSA had fewer tight junctions (TJs) than control and HSA-treated cells, and addition of the anti-VEGF antibody did not restore the original number of TJs. CONCLUSION: TDI increases the permeability of HBE cell monolayers, partly through a VEGF-mediated pathway. This suggests the importance of VEGF in TDI-induced pulmonary diseases, but shows that other pathways may be involved in the pathogenic process.

Transcriptomic analysis of F344 rat nasal epithelium suggests that the lack of carcinogenic response to glutaraldehyde is due to its greater toxicity compared to formaldehyde.

Formaldehyde is cytotoxic and carcinogenic to the rat nasal respiratory epithelium inducing tumors after 12 months. Glutaraldehyde is also cytotoxic but is not carcinogenic to nasal epithelium even after 24 months. Both aldehydes induce similar acute and subchronic histopathology that is characterized by inflammation, hyperplasia, and squamous metaplasia. Because early aldehyde-induced lesions are microscopically similar, we investigated whether transcriptional patterns using cDNA technology could explain the different cancer outcomes. Treatments included 1-, 5-, or 28-day exposure by nasal instillation of formaldehyde solution (400 mM) or glutaraldehyde solution (20 mM). Animals were euthanized and the nasal respiratory epithelium removed for gene expression analysis and a subset of rats treated for 28 days was processed for microscopic examination. RNA was isolated and processed for expression assessment using Clontech Atlas Toxicology II Arrays. Both aldehydes induced hyperplasia, squamous metaplasia, and inflammatory infiltrates with scattered apoptotic bodies in the epithelium covering luminal surfaces of the nasoturbinate, maxilloturbinate, and nasal septum. A subset of 80 genes that were the most variant between the treated and control included the functional categories of DNA repair and apoptosis. Hierarchical clustering discriminated chemical treatment effects after 5 days of exposure, with 6 clusters of genes distinguishing formaldehyde from glutaraldehyde. These data suggest that although both aldehydes induced similar short-term cellular phenotypes, gene expression could distinguish glutaraldehyde from formaldehyde. The gene expression patterns suggest that glutaraldehyde's lack of carcinogenicity may be due to its greater toxicity from lack of DNA-repair, greater mitochondrial damage, and increased apoptosis.