Uncovering seed vigor responsive miRNA in hybrid wheat and its parents by deep sequencing.

BACKGROUND: Two-line hybrid wheat technology system is one way to harness wheat heterosis both domestically and internationally. Seed vigor is a crucial parameter for assessing seed quality, as enhanced seed vigor can lead to yield increments of over 20% to a certain extent. MicroRNAs (miRNAs) were known to participate in the development and vigor of seed in plants, but its impact on seed vigor in two-line hybrid wheat remains poorly elucidated. RESULTS: The hybrid (BS1453/11GF5135) wheat exhibited superiority in seed vigor and anti-aging capacity, compared to its male parent (11GF5135, MP) and female parent (BS1453, FP). We identified four miRNAs associated with seed vigor, all of which are novel miRNAs. The majority of targets of miRNAs were related to ubiquitin ligases, kinases, sucrose synthases and hydrolases, involving in starch and sucrose metabolism, hydrolysis, catalysis, plant hormone signal transduction, and other pathways, which played crucial roles in seed development. Additionally, we also found miR531 was differentially expressed in both male parent and hybrid, and its target gene was a component of the E1 subunit of α-ketoate dehydrogenase complex, which interacted with dihydrolipoamide acetyltransferase (E2) and dihydrolipoyl dehydrogenase (E3). Finally, We established a presumptive interaction model to speculate the relationship of miR531 and seed vigor. CONCLUSIONS: This study analyzed the seed vigor of two-line hybrid wheat, and screened seed vigor-related miRNAs. Meanwhile speculated the genetic relationship of hybrid and parents, in terms of miRNAs. Consequently, the present study provides new insights into the miRNA-mediated gene and protein interaction network that regulates seed vigor. These findings hold significance for enhancing the yield and quality of two-line hybrid wheat, facilitating its future applications.

Transcriptome analysis of wheat seedling and spike tissues in the hybrid Jingmai 8 uncovered genes involved in heterosis.

MAIN CONCLUSION: Transcriptome analysis was carried out for wheat seedlings and spikes from hybrid Jingmai 8 and both inbred lines to unravel mechanisms underlying heterosis. Heterosis, known as one of the most successful strategies for increasing crop yield, has been widely exploited in plant breeding systems. Despite its great importance, the molecular mechanism underlying heterosis remains elusive. In the present study, RNA sequencing (RNA-seq) was performed on the seedling and spike tissues of the wheat (Triticum aestivum) hybrid Jingmai 8 (JM8) and its homozygous parents to unravel the underlying mechanisms of wheat heterosis. In total, 1686 and 2334 genes were identified as differentially expressed genes (DEGs) between the hybrid and the two inbred lines in seedling and spike tissues, respectively. Gene Ontology analysis revealed that DEGs from seedling tissues were significantly enriched in processes involved in photosynthesis and carbon fixation, and the majority of these DEGs expressed at a higher level in JM8 compared to both inbred lines. In addition, cell wall biogenesis and protein biosynthesis-related pathways were also significantly represented. These results confirmed that a combination of different pathways could contribute to heterosis. The DEGs between the hybrid and the two inbred progenitors from the spike tissues were significantly enriched in biological processes related to transcription, RNA biosynthesis and molecular function categories related to transcription factor activities. Furthermore, transcription factors such as NAC, ERF, and TIF-IIA were highly expressed in the hybrid JM8. These results may provide valuable insights into the molecular mechanisms underlying wheat heterosis.

Interleukin-15 inhibits the expression of differentiation markers induced by Ca(2+) in keratinocytes.

Interleukin (IL)-15 is an important proinflammatory cytokine that can protect epidermal keratinocytes (KCs) from ultraviolet-induced apoptosis and plays a role in the pathogenesis of psoriasis. However, the impact of IL-15 on KC differentiation remains unknown. In this study, isolated human primary epidermal KCs were treated with various concentrations of IL-15 for different times, and the expression of differentiation markers (keratin 1, involucrin and loricrin) and p53 as well as the activation of ERK, AKT and Notch induced by IL-15 in the absence or presence of Ca(2+) was detected by real-time PCR and Western blot. The results showed that stimulation with Ca(2+) alone increased the expression of KC differentiation markers and p53 and promoted the activation of Notch1. Pretreatment with IL-15 resulted in a decrease in the Ca(2+) -induced expression of KC differentiation markers and p53. Additionally, Ca(2+) continually inhibited the phosphorylation of ERK1/2 and activated AKT, and IL-15 reduced the effect of Ca(2+) on ERK1/2 and AKT. FR180204, a specific inhibitor of ERK1/2 phosphorylation, slightly attenuated the effect of Ca(2+) on the expression of differentiation markers and p53 and the activation of Notch1. In contrast, MK-2206, an inhibitor of pAKT, strongly blocked the expression of the differentiation markers and p53 and the activation of Notch1. An anti-IL-15 antibody neutralized the effect of IL-15 on KC differentiation. These results indicate that IL-15 inhibits the Ca(2+) -induced differentiation of KCs, mainly via the attenuation of Ca(2+) -stimulated PI3K-AKT signalling.

The activation of TLR7 regulates the expression of VEGF, TIMP1, MMP2, IL-6, and IL-15 in Hela cells.

Toll-like receptors (TLRs) play important roles in activation of immunoreaction and tumor development. Toll-like receptor 7 (TLR7), one of the TLRs binding with single-stranded RNA, activates intracellular pathways and stimulates the release of proinflammatory cytokines, chemokines. In this study, we investigated the impact of the TLR7-signaling pathway on the expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase 2 (MMP2), tissue inhibitor of metalloproteinase 1 (TIMP1), interleukin 6 (IL-6), and interleukin 15 (IL-15), which have been testified to refer to the immunomodulating and tumor progression. We confirmed that the TLR7 was expressed by Hela cells, despite the abundance was weak. Gardiquimod, one of the TLR7 ligands, can promote these five genes expression in varying degrees. After stimulating with gardiquimod, the expression of the IL-15V1, 3 increased about 4.5 times on RNA level, the other expression was only up-regulated about 2 times. We also discovered that gardiquimod could activate the MAPK/ERK- and PI3K/AKT-signaling pathways, and the specific inhibitors studies indicate that, the effect of gardiquimod on these genes expression is mainly or partially dependent on the activation of these two signaling pathways. To sum up, the activation of TLR7 signaling pathway may modulate some genes expression in Hela cells and may contribute to the pathogenesis of the cervical cancer.

Cold atmospheric plasma-activated saline alleviates secondary injury post-SCI by inhibiting extracellular matrix remodeling and infiltration of proinflammatory macrophages.

BACKGROUND: Cold atmospheric plasma (CAP) has been shown to improve the recovery of transected peripheral nerves. We determined the protective role of CAP-activated saline (CAP-AS) treatment in the acute and subacute stages of spinal cord injury (SCI) in mice. METHODS: C57BL/6 SCI mice were treated with CAP-AS for 14 days. Injury recovery was assessed weekly for four weeks by conducting motor function tests, including the Basso Mouse Scale (BMS) and footprint test. Transcriptome analysis was conducted on day 14 to elucidate potential mechanisms, which were further validated through immunofluorescence examinations of the injured spinal cord tissues on day 28 and the levels of proinflammatory cytokines produced by macrophages in vitro. RESULTS: Compared to the SCI group, the CAP-AS-treated groups presented significantly better hindlimb motor function after four weeks. The downregulated (SCI vs. SCI + CAP-AS, with CAP-AS activated for 20 min) differentially expressed genes (DEGs) were enriched in the extracellular region, extracellular matrix (ECM), and ECM-receptor interaction. In contrast, the upregulated DEGs were enriched in immune response-associated pathways. Histological changes in the CAP-AS-treated groups were observed to further validate the predicted mechanisms 28 days post-injury. The alleviation of secondary injury was confirmed by an increase in GFAP-positive and NFH-positive areas, and enhanced outgrowth of 5-HT-positive fibers. Inhibited ECM remodeling was confirmed by a decrease in the areas positive for PDGFRß, fibronectin, and laminin. A decrease in the infiltration of macrophages and activation of microglia was determined by a decrease in CD68-positive and F4/80-positive areas. The inhibitory effect of CAP-AS on inflammation was further supported by a decrease in the levels of the proinflammatory cytokines IL-1ß, IL-6, and TNF-α in CAP-AS-treated M1 macrophages. CONCLUSION: CAP-AS can alleviate secondary injury in SCI model mice by inhibiting ECM remodeling in injured tissues and reducing the infiltration or activation of proinflammatory macrophages/microglia.

Gardiquimod inhibits the expression of calcium-induced differentiation markers in HaCaT cells.

Toll-like receptor 7 (TLR7) is an important member in pattern recognition receptors families. TLR7 signal pathway is involved in the physiological process in many type cells, but the impact of TRL7 on differentiation in the human keratinocytes is still unknown. In this study, we investigated the expression of TLR7 in keratinocytes, and the effect of TLR7 agonist gardiquimod on the expression of calcium (Ca(2+))-induced keratinocytes differentiation markers in HaCaT cells. Immunohistochemistry and western-blotting analysis showed that TLR7 is expressed in basal keratinocytes of normal skin and in the human keratinocyte cell line HaCaT, but not expressed in the keratinocytes of psoriasis lesions. Pretreatment with gardiquimod could down-regulate Ca(2+)-induced differentiation marker expression and activate Raf-MEK-ERK and PI3K-AKT signal pathways in HaCaT cells. However, specific inhibitors studies showed that the down-regulation of the differentiation markers expression by gardiquimod was not dependent on the activation of these two pathways. TLR7 may play an important role in the pathogenesis of psoriasis through regulating the differentiation of the keratinocytes, and will give a new insight into the psoriasis.

Interleukin-6 up-regulates the expression of interleukin-15 is associated with MAPKs and PI3-K signaling pathways in the human keratinocyte cell line, HaCaT.

Interleukin (IL)-15 is an important inflammatory cytokine and plays a key role in autoimmune disease. At present, IL-15 gene expression and regulation related to many innate immunity trigger signals have been clarified in some specific cell types, but the relationship of IL-6 and IL-15 in the human keratinocyte cell line (HaCaT) is unknown. In this study, we investigated the effect of IL-6 on the expression of IL-15 and selected signaling pathways in HaCaT cells. Results demonstrated that IL-6 up-regulated the expression of IL-15 both at the mRNA and protein levels. Meanwhile, IL-6 was able to activate MAPKs-ERK1/2 and PI3K-AKT signaling pathways. Furthermore, the high expression of IL-15 induced by IL-6 was down-regulated while MAPKs-ERK1/2 and PI3K-AKT signaling pathways were, respectively, blocked by PD98059 and LY294002. These findings indicate that the expression of IL-15 up-regulated by IL-6 is associated with MAPKs-ERK1/2 and PI3K-AKT signaling pathways in HaCaT cells.

Interleukin 29 enhances expression of Toll receptor 3 and mediates antiviral signals in human keratinocytes.

OBJECTIVE: Interleukin 29 (IL-29) is a class II cytokine and displays numerous immune functions other than its anti-viral and antiproliferation activities. This study is focused on the effect of IL-29 on human keratinocytes (KCs). METHODS: Primary KCs were stimulated by various concentrations of IL-29 for different time periods, and antiviral proteins and TLR3 gene expression were then analyzed by real-time PCR. The signal pathways activated by IL-29 in KCs were detected by western blot. The antiviral activity of IL-29 was determined by methylthiazolyldiphenyl-tetrazolium bromide, and small interfering RNA knockdown was used to analyze the role of toll receptor 3 (TLR3) in the antiviral activity of IL-29. RESULTS: IL-29 was able to induce expression of antiviral proteins and TLR3 gene expression in KCs. IL-29 pretreatment strongly enhanced herpes simplex virus type 1 (HSV-1)-induced expression of the interferon ß (IFN-ß) gene and protected the KCs from HSV-1 challenge. The IL-29 antiviral activity was partially dependent on TLR3 expression induced by this cytokine, and mechanistic studies demonstrated that the regulation of TLR3 expression by IL-29 might be partially dependent on Janus kinase /signal transducer and activator of transcription (JAK-STATs) activation. CONCLUSION: IL-29-induced TLR3 expression is involved in antiviral activity of IL-29 in KCs, which suggests a feasible method to cure certain viral infections of the skin.

IL-29 and IFN-α regulate the expression of MxA, 2',5'-OAS and PKR genes in association with the activation of Raf-MEK-ERK and PI3K-AKT signal pathways in HepG2.2.15 cells.

Interferons (IFNs) can activate the PI3K-AKT and Raf-MEK-ERK signal pathways and induce antiviral proteins (MxA, 2',5'-OAS and PKR) expression in specific cell lines. However, the relationship between those antiviral proteins expression and signal pathways remains unknown at present. Thus our experiments were designed to determine the exact relationship in HepG2.2.15 cell line. The results demonstrated that IFN-α and IL-29 were both able to activate PI3K-AKT and Raf-MEK-ERK signal pathways, and IFN-α up-regulated the expression of MxA, 2',5'-OAS and PKR whereas IL-29 increased mRNA expression of MxA and 2',5'-OAS and had no influence on PKR. Furthermore, MxA, 2',5'-OAS and PKR expression were down-regulated while PI3K-AKT signal pathway was blocked by LY294002. And MxA was up-regulated after Raf-MEK-ERK signal pathway being blocked by PD98059. These findings indicate that the expression of MxA, 2',5'-OAS and PKR are up-regulate by PI3K-AKT signal pathway, and Raf-MEK-ERK signal pathway has a negative regulatory effect on the expression of MxA and no significant effect on 2',5'-OAS and PKR.

A single-nucleotide polymorphism of the TNFSF4 gene is associated with systemic lupus erythematosus in Chinese Han population.

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. Recently, single-nucleotide polymorphisms (SNPs) in tumor necrosis factor (TNF) superfamily gene TNFSF4 have been shown to be associated with SLE in European and Hong Kong Chinese populations. But it is unknown whether it is also associated with the disease in Mainland Chinese Han population. We genotyped the SNPs rs1234315 near the TNFSF4 gene in 1,344 SLE patients and 4,315 controls of Chinese Han population and confirmed the association between the SNP and the SLE [odds ratios (ORs) of 1.45 and P values of 1.5 × 10(-16)]. The stratification analyses showed that rs1234315 was more strongly associated with SLE patients with arthritis. Our study not only suggested that the TNFSF4 gene was associated with SLE in Chinese Han population, but also implied that it might be a common genetic factor predisposing to the development of SLE in multiple populations.

The influence of high-frequency repetitive transcranial magnetic stimulation on endogenous estrogen in patients with disorders of consciousness.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a promising therapeutic intervention for neurological disorders. However, the precise mechanisms of rTMS in neural excitability remains poorly understood. Estradiol is known to have strong influence on cortical excitability. This study aimed to determine whether high-frequency (HF) rTMS influences endogenous estradiol in male patients with disorders of consciousness (DOC). METHODS: A randomized controlled trial was conducted with a total of 57 male patients with DOC. Eventually, 50 patients completed the study. Twenty-five patients underwent real rTMS, and 25 patients underwent sham rTMS, which were delivered over the dorsolateral prefrontal cortex. The primary outcome measure was the change in serum estradiol from baseline to after 10 sessions of HF-rTMS. The improvement in the total score of the JFK Coma Recovery Scale-Revised (CRS-R) was also assessed. RESULTS: Changes in estradiol levels and CRS-R scores from pre-to post-treatment were significantly different between the active rTMS and sham stimulation conditions. A significant enhancement of CRS-R scores in the patients receiving rTMS stimulation was observed compared to the sham group. Serum estradiol levels in patients following HF-rTMS were significantly higher than their baseline levels, whereas no significant changes were found in the sham group from pre-to post-stimulation. The rise in estradiol levels was greater in responders than in non-responders. The changes in estradiol levels were significantly positively correlated with the improvement in CRS-R scores. CONCLUSION: These preliminary findings indicate that serum estradiol levels are affected by HF-rTMS and positively related to clinical responses in male patients with DOC. The elevation of estradiol levels may lay a physiological foundation for successful rTMS treatment for DOC patients by increasing cortical excitability.

[Protective role of MMP-9 inhibitor batimastat in acute lung injury after cardiopulmonary bypass].

OBJECTIVE: To investigate the protective effect of exogenous inhibitor of matrix metalloproteinases-9 (MMP-9), batimastat, in the lung injury induced by cardiopulmonary bypass (CPB) in dogs. METHODS: Thirty healthy mongrel puppies were randomly divided into 3 groups: control group, low-dose group [batimastat 10 mg/(kg.d) for 3 days before operation] and high-dose group [batimastat 30 mg/(kg.d) for 3 days before operation]. The off-pump puppies' model of acute lung injury was established, and hemodynamic and respiratory parameters were monitored. The preoperative and postoperative alveolar-arterial oxygen difference (A-aDO(2)) and respiratory index (RI) were calculated. From the beginning of surgery, blood samples were taken at the time 0, 60, 120, and 270 min. Plasma concentrations of MMP-9 were measured by ELISA, and blood MMP-9 mRNA expressions were determined by RT-PCR. The myeloperoxidase (MPO) activity of centrifugal bronchoalveolar lavage fluid were measured by Colorimetry. And MMP-9 activity was determined by Gelatin zymography. Light and electronic microscope were used to observe the morphological changes of lung tissue. A small piece of left lung tissue was taken, weighed and baked to calculate the wet weight (W/D) index. RESULTS: After cardiopulmonary bypass, the concentrations of MMP-9 and mRNA expressions of the control group were increased significantly, and lung injury was apparent. At 270 min, the MMP-9 plasma concentration of high-dose group (17.36 +/- 1.18) microg/L was significant reducing than control group (30.47 +/- 2.22) microg/L (P < 0.05). After operation, A-aDO(2) and RI of high-dose group were significantly improved than control group (P < 0.05). The W/D index of the high-dose group (2.8 +/- 0.48) was significantly lower than that of control group (4.7 +/- 0.6) (P < 0.05). And the pathological changes of lung tissue were significantly improved in the high-dose group. However, there was no significant difference in the MMP-9 mRNA expression in three groups. CONCLUSIONS: Batimastat plays a role in the protection of the lung injury of CBP by reducing the concentration and activity of MMP-9, the degradation of the cell membrane and pulmonary neutrophil infiltration and reduction of pulmonary edema.

Poly-L-Arginine Induces Apoptosis of NCI-H292 Cells via ERK1/2 Signaling Pathway.

Cationic protein is a cytotoxic protein secreted by eosinophils and takes part in the damage of airway epithelium in asthma. Poly-L-arginine (PLA), a synthetic cationic protein, is widely used to mimic the biological function of the natural cationic protein in vitro. Previous studies demonstrated the damage of the airway epithelial cells by cationic protein, but the molecular mechanism is unclear. The purpose of this study aimed at exploring whether PLA could induce apoptosis of human airway epithelial cells (NCI-H292) and the underlying mechanism. Methods. The morphology of apoptotic cells was observed by transmission electron microscopy. The rate of apoptosis was analyzed by flow cytometry (FCM). The expressions of the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), Bcl-2/Bax, and cleaved caspase-3 were assessed by western blot. Results. PLA can induce apoptosis in NCI-H292 cells in a concentration-dependent manner. Moreover, the phosphorylation of the ERK1/2 and the unbalance of Bcl2/Bax, as well as the activation of caspase-3, were involved in the PLA-induced apoptosis. Conclusions. PLA can induce the apoptosis in NCI-H292 cells, and this process at least involved the ERK1/2 and mitochondrial pathway. The results could have some indications in revealing the apoptotic damage of the airway epithelial cells. Besides, inhibition of cationic protein-induced apoptotic death in airway epithelial cells could be considered as a potential target of anti-injury or antiremodeling in asthmatics.

Wnt-3a protein promote neuronal differentiation of neural stem cells derived from adult mouse spinal cord.

BACKGROUND: Wnt proteins as growth factor have multiple functions in neural development, and especially serve key roles in differentiation and development. Wnt-3a is an intercellular signaling molecule that is involved in a variety of morphogenetic events. The purpose of this study was to investigate the effects of Wnt-3a signal protein on proliferation and differentiation of neural stem cells derived from adult mouse spinal cord. METHODS: Adult mouse neural stem cells were cultured with serum free incubation. The recombined plasmid pSecTag2/Hygro B-Wnt3a for eukaryotic expression transfected adult neural stem cell, then the expression protein was detected by Western blot. The differentiation of adult neural stem cells was identified by the immunocytochemical technique. RESULTS: The inducing differentiated rates of neurons were improved greatly by Wnt-3a protein compared with control (p<0.05). CONCLUSION: Wnt-3a has obvious influence on the neuronal differentiation of adult neural stem cell.

Disorder of the mevalonate pathway inhibits calcium-induced differentiation of keratinocytes.

Mutation of genes encoding the enzymes of the mevalonate pathway cause a variety of diseases, including skin disorders. Mutation of four genes in this pathway, including mevalonate kinase, phosphomevalonate kinase, mevalonate diphosphate decarboxylase and farnesyl diphosphate synthase, have demonstrated to be responsible for porokeratosis (PK). However, the pathogenesis of PK remains unclear. In the present study, specific enzyme inhibitors of the mevalonate pathway, including pravastatin (PRA), alendronate (ALD), farnesyl transferase inhibitor (FTI­277) and geranylgeranyl transferase inhibitor (GGTI­298), were used to investigate the effect on differentiation of keratinocytes (KCs). Western blotting demonstrated that PRA, ALD, FTI­277 or GGTI­298 alone, or in combination, inhibited the expression level of calcium­induced differentiation maker involucrin (INV) in KCs. ALD and PRA induced greater inhibition of INV compared with FTI­277 and GGTI­298 treatment. These inhibitors additionally influenced the expression levels of keratin1. Mechanistic studies revealed that treatment of cells with inhibitors decreased the expression levels of p53 and Notch1, and regulated activation of the mitogen activated protein kinase and phosphoinositide­3­kinase/protein kinase B signaling pathways. The results of the present study suggested that regulation of the mevalonate pathway may be necessary for differentiation of KCs, and the pathogenesis of disseminated superficial actinic PK.

LPS Cooperates with Poly-L-Arginine to Promote IL-6 and IL-8 Release via the JNK Signaling Pathway in NCI-H292 Cells.

Objective. Herein, we aimed to study the mechanism whereby poly-L-arginine (PLA) and lipopolysaccharide (LPS) can synergistically induce the release of interleukin-6 (IL-6) and IL-8 in NCI-H292 cells. Methods. NCI-H292 cells were divided into control, PLA, LPS, and PLA+LPS groups. At various time points, the phosphorylation of JNK in each group was measured by western blotting. Additionally, the productions of IL-6 and IL-8 were assessed using an enzyme-linked immunosorbent assay (ELISA). The effects of SP600125, an inhibitor of the JNK pathway, on the increase of p-JNK, IL-6, and IL-8 were also studied. Results. Our results showed that either PLA or LPS treatment alone can significantly increase the phosphorylation level of JNK in NCI-H292 cells. Of interest was the combined use of PLA and LPS that has a synergistic effect on the phosphorylation of JNK, as well as synergistically inducing the release of IL-6 and IL-8 in NCI-H292 cells. Furthermore, SP600125 significantly inhibited the activation of JNK signal, as well as reducing the productions of IL-6 and IL-8 in response to PLA+LPS stimulation. Conclusions. The JNK signaling pathway contributes to the release of IL-6 and IL-8, which is stimulated by the synergistic actions of PLA+LPS in NCI-H292 cells.

Poly-L-Arginine Acts Synergistically with LPS to Promote the Release of IL-6 and IL-8 via p38/ERK Signaling Pathways in NCI-H292 Cells.

Major basic protein (MBP) derived from activated eosinophil can exacerbate atopic asthma induced by lipopolysaccharide (LPS). The pharmacological function of MBP can be mimicked by poly-L-arginine (PLA), however, the potential signaling mechanisms of LPS-PLA-induced release of the inflammatory cytokines interleukin (IL)-6 and IL-8 remain unclear. In the present study, airway epithelia NCI-H292 cell lines were treated with LPS and/or PLA. We found that the expression levels of IL-6 and IL-8 induced by LPS-PLA were increased significantly compared with that in untreated cells. Meanwhile, the phosphorylation of p38 MAPK and ERK1/2 was also up-regulated dramatically by LPS-PLA, but this increase could be blocked by specific inhibitor. Importantly, blocking the phosphorylation of p38 MAPK and ERK1/2 reduced the expression levels of IL-6 and IL-8 as well. Collectively, LPS-PLA-induced release of IL-6 and IL-8 from NCI-H292 cells may be due to the synergistic activation of p38 MAPK and ERK1/2 signaling transduction pathways.

Activation of Toll-like receptor 7 regulates the expression of IFN-λ1, p53, PTEN, VEGF, TIMP-1 and MMP-9 in pancreatic cancer cells.

Toll-like receptors (TLRs) are critical in the induction of the immune response in tumor development. TLR7 has previously been demonstrated to be associated with the development of pancreatic cancer, and the release of cytokines and chemokines from other types of cancer cell; however, the specific expression induced by TLR7 agonists in pancreatic cancer cells remains to be elucidated. The present study aimed to investigate the effects of the TLR7 agonist, gardiquimod, on ERK1/2 signaling pathway, and on the expression of genes involved in the pathogenesis of cancer, including phosphatase and tensin homolog deleted on chromosome 10 (PTEN), p53, type Ⅲ interferon (IFN-λ1), vascular endothelial growth factor (VEGF), matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1). The results demonstrated that activation of TLR7 upregulated the expression levels of certain genes to varying degrees; the expression levels of IFN-λ1 and MMP-9 were increased by ~3 fold, whereas other genes (p53, PTEN, TIMP-1) were upregulated by ~2 fold, and VEGF was marginally upregulated after 10 min. Furthermore, gardiquimod increased the expression levels of phosphorylated-extracellular signal-regulated kinase (ERK)1/2. In addition, PD98059, a specific inhibitor of ERK phosphorylation, inhibited the ability of gardiquimod to activate ERK1/2; consequently weakening the effect of gardiquimod on gene regulation. These findings indicated that the effect of TLR7 agonists, including gardiquimod, on gene expression in BxPC-3 pancreatic cancer cells was partly associated with the mitogen-activated protein kinase-ERK1/2 signaling pathway.

Activation of Toll-like receptor 7 inhibits the proliferation and migration, and induces the apoptosis of pancreatic cancer cells.

Pancreatic cancer is one of the most malignant types of tumor and has a poor prognosis. Toll­like receptor 7 (TLR7) has been found to be present and have different roles in different types of cancer cells. In the present study, the roles of TLR7 in BxPC­3 cells, a human pancreatic adenocarcinoma cell line, were investigated. The cells were treated with gardiquimod, an agonist of TLR7, following which the properties of the cells, including proliferation, migration, cell cycle and apoptosis, were analyzed. It was revealed that activation of TLR7 by gardiquimod inhibited cell proliferation and migration, and induced apoptosis of the cells. In addition, gardiquimod downregulated the expression levels of cyclin B1, cyclin E and B­cell lymphoma 2, while upregulating the expression of B­cell­associated X protein. These results suggested that the activation of TLR7 suppresses the progression of pancreatic cancer.