The present study was designed to examine the expression and function of matrix metalloproteinase‑19 (MMP‑19), which is downregulated following respiratory syncytial virus (RSV) infection. The diverse expression levels of MMP were examined using a designed cDNA expression array. The expression and secretion of MMP‑19 was examined using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis and ELISA, respectively. The proliferation of epithelial cells and lung fibroblasts were examined using flow cytometry. The epithelial‑mesenchymal transition (EMT) was also examined by performing western blot and RT‑qPCR analyses. The results of the cDNA assay showed that infection with RSV resulted in the abnormal expression of certain metalloproteinases. Among these, the expression of MMP‑19 decreased 3 and 7 days following infection. By using flow cytometric, western blot and RT‑qPCR analyses, the present study demonstrated that the downregulation of MMP‑19 inhibited the proliferation of epithelial cells, promoted the EMT and induced the proliferation of lung fibroblasts. Taken together, the findings of the present study suggested that the downregulation of MMP‑19 following RSV infection may be associated with the development of airway hyper‑responsiveness.

Myocardial hypertrophy (MH) is an independent risk factor for cardiovascular disease, which in turn lead to arrhythmia or heart failure. Therefore, attention must be paid to formulation of therapeutic strategies for MH. Puerarin is a key bioactive ingredient isolated from Pueraria genera of plants that is beneficial for the treatment of MH. However, its molecular mechanism of action has not been fully determined. In the present study, 40 µM puerarin was demonstrated to be a safe dose for human AC16 cells using Cell Counting Kit‑8 assay. The protective effects of puerarin against MH were demonstrated in AC16 cells stimulated with isoproterenol (ISO). These effects were characterized by a significant decrease in surface area of cells (assessed using fluorescence staining) and mRNA and protein expression levels of MH‑associated biomarkers, including atrial and brain natriuretic peptide, assessed using reverse transcription‑quantitative PCR and western blotting, as well as β‑myosin heavy chain mRNA expression levels. Mechanistically, western blotting demonstrated that puerarin inhibited activation of the Wnt signaling pathway. Puerarin also significantly decreased phosphorylation of p65; this was mediated via crosstalk between the Wnt and NF‑κB signaling pathways. An inhibitor (Dickkopf‑1) and activator (IM‑12) of the Wnt signaling pathway were used to demonstrate that puerarin‑mediated effects alleviated ISO‑induced MH via the Wnt signaling pathway. The results of the present study demonstrated that puerarin pre‑treatment may be a potential therapeutic strategy for preventing ISO‑induced MH and managing MH in the future.

The present study investigated the contribution of bone marrow-derived mesenchymal stem cells (BM‑MSCs) to neointimal formation, and whether endothelial‑like cells (ELCs) differentiated from BM‑MSCs could attenuate intimal hyperplasia following vascular injury. BM‑MSCs were isolated from rat femurs and tibias and expanded ex vivo. Differentiation into ELCs was induced by cultivation in the presence of 50 ng/ml vascular endothelial growth factor (VEGF). MSCs and ELCs were labeled with BrdU and injected via the femoral vein on the day of a balloon‑induced carotid artery injury. Carotid artery morphology and histology were examined using ultrasound biomicroscopy and immunohistochemistry. Flow cytometry analysis measured CD31 and CD34 expression, and immunofluorescence analysis measured von Willebrand factor and VEGF receptor 2 expression in ELCs. Ultrasound biomicroscopy observed a significantly increased intima‑media thickness in the phosphate‑buffered saline (PBS) and BM‑MSCs groups compared with the ELCs group. Intima/media ratios were significantly reduced in the ELCs group compared with the PBS and BM‑MSCs groups. At 4 weeks of administration, the cells labeled with BrdU were abundantly located in the adventitial region and neointima. MSCs were able to differentiate into ELCs in vitro. Cell therapy with BM‑MSCs was not able to attenuate neointima thickness, however transplantation with ELCs significantly suppressed intimal hyperplasia following vascular injury.

Behcet's disease is a multi‑system inflammatory disorder, and ocular Behcet's disease (OBD) is one of the most common causes of uveitis in China. A number of studies have indicated that Th17 cells, a subset of interleukin-17 (IL-17)-producing CD4+ T‑helper cells, serve important roles in the pathogenesis of OBD. Berberine (BBR) is an isoquinoline derivative alkaloid isolated from Chinese herbs, and has been used traditionally for the treatment of gastrointestinal disorders. The aim of the present study was to investigate the effect of BBR on Th17 cell proliferation and cytokine secretion, and the expression and activation of the signal transducer and activator of transcription 3 (STAT3) transcription factor in OBD in vitro. Blood samples were obtained from healthy controls and patients with active ocular Behcet's disease. Peripheral blood mononuclear cells (PBMCs) or CD4+ T cells were cultured for three days with or without BBR and in the presence of anti‑CD3 and anti‑CD28 antibodies. IL‑17 expression in cell sample supernatants was determined by enzyme‑linked immunosorbent assay, and cell viability was measured using the Cell Counting kit‑8 assay. The number of CD4+IL‑17+ cells and the expression level of phosphorylated (p)‑STAT3 in CD4+ T cells was determined using flow cytometry analysis. The expression of IL‑17 was increased in patients with active OBD following the activation of PBMCs and CD4+ T cells with anti‑CD3 and anti‑CD28 antibodies when compared with healthy controls. However, no significant difference in cell viability following exposure to BBR was observed in PBMCs derived from healthy controls or patients with OBD. Following incubation with BBR, the expression of IL‑17 was reduced and the number of CD4+IL‑17+ cells was decreased in patients with active OBD and healthy controls. Furthermore, the expression of p-STAT3 was significantly decreased in the presence of BBR in healthy controls. In conclusion, the results of the present study demonstrate that BBR may suppress the Th17 response in patients with OBD by reducing STAT3 phosphorylation. BBR may be a potential therapeutic agent for the treatment of OBD.

Salvianolic acid B (Sal B) is a potential cytotoxic polyphenol against cancer. In the present study the effect of Sal B and its molecular mechanism were investigated in the non‑small cell lung cancer (NSCLC) A549 cell line. The TGF‑β/MAPK/Smad signaling axis was explored. A549 cells were co‑cultured with and without different concentrations of Sal B (25, 50 and 100 µM respectively) and TGF‑β1 (9 pM) for 24 h. Cell epithelial‑mesenchymal transition (EMT), cell migration, cell cycle distribution, autophagy and apoptosis were assessed by western blotting (WB), wound healing assay and flow cytometry, respectively. Moreover, activation of MAPK, Smad2/3 and the downstream target, plasminogen activator inhibitor 1 (PAI‑1), were assessed by WB. The results demonstrated that Sal B inhibited TGF‑β1‑induced EMT and migration of A549 cells, hampered cell cycle progression and induced cell autophagy and apoptosis. Furthermore, Sal B inactivated MAPK signaling pathways and the phosphorylation of Smad2/3, especially the phosphorylation of Smad3 at the linker region, which resulted in decreased protein expression levels of PAI‑1 in TGF‑β1‑stimulated A549 cells. Overall, these results demonstrated that Sal B may have a potential therapeutic effect against NSCLC in vitro. The results of the present study indicated that the underlying active mechanism of Sal B in NSCLC may be closely related to the impeded activation of the MAPK and Smad2/3 signaling pathways. Therefore, Sal B may be a potential candidate NSCLC therapeutic agent.

Serotonin‑selective reuptake transporter (SERT) regulates extracellular availability of serotonin (5‑hydroxytryptamine; 5‑HT) and participates in the pathogenesis of functional disorders. Colonic SERT expression is decreased in colonic sensitized rats, and the glucagon‑like peptide‑1 analogue, exendin‑4, reduces visceral hypersensitivity by decreasing 5‑HT levels and increasing SERT expression. The present in vitro study aimed to further investigate the effects of exendin‑4 on SERT expression, and to examine the role of GLP‑1 and its receptor in the regulation of 5‑HT. SERT mRNA and protein expression levels were detected by reverse transcription‑quantitative PCR and western blotting. A [3H]‑5‑HT reuptake experiment was performed in IEC‑6 rat intestinal epithelial cells treated with exendin‑4. Effects on the adenosine cyclophosphate (AC)/PKA pathway were examined by variously treating cells with the AC activator forskolin, the protein kinase A (PKA) inhibitor H89 and the AC inhibitor SQ22536. Exendin‑4 treatment upregulated SERT expression and enhanced 5‑HT reuptake in IEC‑6 cells. Also, PKA activity in IEC‑6 cells was increased by both exendin‑4 and forskolin, whereas these effects were abolished by the pre‑treatment of exendin‑9, which is a GLP‑1R inhibitor, SQ22536 and H89. In conclusion, exendin‑4 may be associated with the upregulation of SERT expression via the AC/PKA signaling pathway.

In the present study, the effects and underlying mechanism of RbAp48 on the radiosensitivity of AGS gastric cancer cells was investigated. Cell proliferation was determined with an MTT assay. Flow cytometry was performed to evaluate the cell cycle and apoptosis. Reverse transcription‑quantitative polymerase chain reaction and western blot analysis were performed to detect mRNA and protein expression, respectively, including RbAp48, phosphoinositide 3‑kinase (PI3K) and protein kinase B (Akt). The results revealed that radiation enhanced the expression level of RbAp48 in AGS cells, and that RbAp48 combined with radiation reduced AGS cell proliferation. In addition, RbAp48 combined with radiation resulted in G2 phase arrest and induced apoptosis via regulation of the PI3K/Akt pathway. In conclusion, it was demonstrated that overexpression of RbAp48 enhanced the radiosensitivity of AGS gastric cancer cells via suppression of PI3K/Akt pathway activity, suggesting that RbAp48 may hold potential as a gene therapeutic strategy in the future, aiding in the treatment of gastric cancer.

Age-related alterations in the renin-angiotensin-aldosterone system (RAAS) have been reported in the cardiovascular system; however, the detailed mechanism of the RAAS component mineralocorticoid receptors (MR) has not been elucidated. The present study aimed to investigate the associations between MR and cardiac aging in rats, as well as the regulatory effects of oxidative stress and mitochondrial abnormalities in the aging process. MR expression in the hearts of male Sprague‑Dawley rats aged 3 months (young rats) and 24 months (old rats) was evaluated in vivo. In addition, in vitro, H9C2 cells were treated with a specific MR antagonist, eplerenone, in order to investigate the molecular mechanism underlying the inhibition of myocyte aging process. The results demonstrated that MR expression was significantly higher in 24‑month‑old rat hearts compared with in 3‑month‑old rat hearts. These changes were accompanied by increased p53 expression, decreased peroxisome proliferator‑activated receptor γ coactivator‑1α expression, decreased mitochondrial renewal as assessed by electron microscopy, increased oxidative stress and decreased superoxide dismutase. In vitro, selective antagonism of MR partially blocked H2O2‑induced myocardial aging as assessed by p16, p21 and p53 expression levels and excessive reactive oxygen species (ROS) accumulation. These results indicated that increased MR expression may drive age‑related cardiac dysfunction via mitochondrial damage, increased ROS accumulation and an imbalanced redox state.

Spinal nitric oxide is involved in the mechanisms of pain generation and transmission during inflammatory and neuropathic pain. The aim of the present study was to explore the role of spinal nitric oxide in the development of bone cancer pain. 2 x 10(5) osteosarcoma cells were implanted into the intramedullary space of right femurs of C3H/HeJ mice to induce a model of ongoing bone cancer. Polymerase chain reaction and immunohistochemical analyses were performed to assess the expression of neuronal nitric oxide synthase (nNOS) and inducible (i)NOS in the spinal cord following inoculation. The results showed that inoculation of osteosarcoma cells induced progressive bone cancer, accompanied with pain-associated behavior. The levels of nNOS mRNA in the spinal cord of tumor mice began to increase at day 10 and then decreased to the level in sham mice at day 14, while iNOS mRNA markedly increased in the tumor group at days 10 and 14. Immunohistochemical analysis showed that nNOS- and iNOS-positive neurons were mainly located in the superficial dorsal horn and around the central canal of the L3-L5 spinal cord. Intrathecal injection of 50 µg NOS inhibitor NG-monomethyl-L-arginine (L-NMMA) attenuated cancer-evoked pain behaviors at day 14. These findings indicated that an upregulation of nNOS and iNOS in the spinal cord is associated with bone cancer pain and suggests that exogenously administered L-NMMA may have beneficial effects to alleviate bone cancer pain.

G protein‑coupled receptor 137 (GPR137) is an integral membrane protein, which belongs to the GPR137 family of cell surface mediators of signal transduction. GPF137 was recently identified; however, its role in human disease onset has remained to be elucidated. GPR137 is highly expressed in multiple human gastric cancer cell lines. A GPR137 short hairpin RNA (shRNA)‑expressing vector was transfected into AGS and MGC80‑3 gastric cancer cells, and the subsequent depletion of GPR137 resulted in a significant reduction in cell proliferation and colony formation, as determined by MTT and colony formation assays. In addition, cell cycle analysis indicated that GPR137 knockdown arrested MGC80‑3 cells in G2/M phase. To the best of our knowledge, the present study was the first to investigate the role of GPR137 in gastric tumorigenesis and revealed that knockdown of GPR137 by lentivirus‑mediated shRNA transfection inhibited the growth of gastric cancer cells in vitro. These results indicated that GPR137 may present a novel target for the development of pharmacological therapeutics for human gastric cancer.

Nasopharyngeal carcinoma (NPC) is endemic in the southern provinces of China and Southeast Asia. It has been reported that microRNA‑122 (miR‑122) and tripartite motif‑containing protein 29 (TRIM29) serve important roles in many types of tumor. The present study aimed to evaluate the expression of miR‑122 and TRIM29, and their clinical significance in NPC, and to examine the associated molecular mechanisms. It was observed that low expression of miR‑122 and high expression of TRIM29 led to a low overall survival rate in patients with NPC, which was associated with tumor‑node‑metastasis (TNM) stage and distant metastasis of NPC. Low expression of miR‑122 was correlated reciprocally with high expression of TRIM29 in NPC tissues, and the two were aggravated by radiation treatment in NPC cell lines. Through Cell Counting kit‑8 and Transwell assays, miR‑122 was demonstrated to be able to inhibit the proliferation, migration and invasion of NPC cells. Through reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analyses, the expression of metastasis‑associated genes, including E‑cadherin, metastatic tumor antigen 1, matrix metalloproteinase‑2 and metalloproteinase inhibitor 2 were demonstrated to be regulated by miR‑122 in NPC cells. Additionally, through a luciferase assay, RT‑qPCR and western blot analysis, it was demonstrated that TRIM29 may be a direct target of miR‑122. In addition, it was noted that miR‑122 decreased the expression of phosphorylated (p) phosphatidylinositol 3‑kinase (PI3K) and p‑RAC‑α serine/threonine‑protein kinase (AKT). Collectively, the results of the present study demonstrated that miR‑122 may exert its tumor suppressive role by targeting TRIM29 and inhibiting the activity of PI3K/AKT signaling. It was indicated that miR‑122 and TRIM29 may be developed as biomarkers of NPC, and possible molecular targets for the prevention of metastasis in patients with NPC.

Accumulating evidence suggests that microRNAs (miRNAs) play a key role in the biological behaviors and progression of glioma. However, the function and bio‑molecular mechanisms of miR‑342 in glioma remain largely unclear. In the present study, reverse transcription quantitative‑polymerase chain reaction and western blotting were performed to determine the mRNA and protein expression levels of the factors investigated. MTT assay was performed to examine the proliferation rates. Luciferase reporter assay was performed to test the binding between miRNA‑342 and its putative target. Data indicated that miR‑342 expression was markedly decreased in human glioma tissues and cell line U87, and reduced miR‑342 expression significantly promoted cell proliferation. In order to explore the mechanisms, G‑protein coupled receptor family C group 5 member A (GPRC5A) was identified as a target of miR‑342 and depletion of GPRC5A suppressed cell proliferation. Our findings demonstrated that miR‑342 regulates the cell proliferation of glioma by targeting GPRC5A, which indicates that miR‑342 is a target of interest regarding the treatment of refractory glioma, and it may provide a promising prognostic and therapeutic strategy for glioma treatment.

The present study aimed to investigate the effects of sufentanil on sepsis-induced acute lung injury (ALI), and identify the potential molecular mechanisms underlying its effect. In order to achieve this, a rat sepsis model was established. Following treatment with sufentanil, the lung wet/dry (W/D) weight ratio was calculated. Histopathological analysis was performed via hematoxylin and eosin staining. Levels of inflammatory factors in bronchoalveolar lavage fluid were determined via ELISA. Furthermore, malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in tissue homogenates were assessed using commercial kits. Western blot analysis was performed to determine kininogen-1 (KNG1) protein expression. In addition, alveolar epithelial type II cells (AEC II) were stimulated with lipopolysaccharide (LPS) to mimic ALI. The levels of inflammation and oxidative stress were evaluated following overexpression of KNG1. Protein expression levels of nuclear factor-κB (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling were determined via western blot analysis. The results of the present study demonstrated that sufentanil alleviated histopathological injury and the W/D ratio in lung tissue. Following treatment with sufentanil, levels of inflammatory factors also decreased, accompanied by decreased concentrations of MDA, and increased activities of SOD, CAT and GSH-Px. Notably, KNG1 was decreased in lung tissues following treatment with sufentanil. Furthermore, overexpression of KNG1 attenuated the inhibitory effects of sufentanil on LPS-induced inflammation and oxidative stress in AEC II. Sufentanil markedly downregulated NF-κB expression, while upregulating Nrf2 and HO-1 expression levels, which was reversed following overexpression of KNG1. Taken together, the results of the present study suggested that sufentanil may alleviate inflammation and oxidative stress in sepsis-induced ALI by downregulating KNG1 expression.