Genetically predicted insomnia causally increases the risk of erectile dysfunction.

Sleep has attracted extensive attention due to its significance in health. However, its association with erectile dysfunction (ED) is insufficiently investigated. To investigate the potential causal links between sleep traits (insomnia, sleep duration, and chronotype) and ED, this study was performed. The single-nucleotide polymorphisms (SNPs) associated with insomnia, sleep duration, and chronotype were retrieved from previous genome-wide association studies (GWAS). A conventional two-sample Mendelian randomization (MR) was used to estimate the causal links between sleep traits and ED. The summary statistics of ED were from individuals of European ancestry (6175 cases vs 217 630 controls). As shown by the random effect inverse-variance-weighting (IVW) estimator, genetically predicted insomnia was causally associated with a 1.15-fold risk of ED (95% confidence interval: 1.07-1.23, P < 0.001). Sleep duration and morningness were not causally associated with ED, as indicated by the IVW (all P > 0.05). These findings were consistent with the results of sensitivity analyses. Based on genetic data, this study provides causal evidence that genetically predicted insomnia increases the risk of ED, whereas sleep duration and chronotype do not.

Vacuum therapy ameliorates erectile dysfunction in bilateral cavernous nerve crush rats by inhibiting apoptosis and activating autophagy.

Postprostatectomy erectile dysfunction (pPED) remains a current problem despite improvements in surgical techniques. Vacuum therapy is clinically confirmed as a type of pPED rehabilitation. However, its underlying mechanisms are incompletely understood. Recently, autophagy and apoptosis were extensively studied in erectile dysfunction resulting from diabetes, senescence, and androgen deprivation but not in the context of pPED and vacuum therapy. Therefore, this study was designed to investigate the roles of autophagy and apoptosis in pPED and vacuum therapy. Twenty-four adult male Sprague-Dawley rats were randomly divided into three groups: the control group, bilateral cavernous nerve crush (BCNC) group, and BCNC + vacuum group. After 4 weeks of treatment, intracavernosal pressure was used to evaluate erectile function. Real-time quantitative polymerase chain reaction, western blot, and immunohistochemistry were used to measure the molecular expression. TdT-mediated dUTP nick-end labeling staining was used to assess apoptosis. Transmission electron microscopy was used to observe autophagosomes. After treatment, compared with those of the BCNC group, erectile function and cavernosal hypoxia had statistically significantly improved (P < 0.05). Apoptosis and the relative protein expression of B-cell lymphoma-2-associated X and cleaved Caspase3 were decreased (P < 0.05). Autophagy-related molecules such as phosphorylated unc-51-like autophagy-activating kinase 1 (Ser757) and p62 were decreased. Beclin1, microtubule-associated protein 1 light chain 3 A/B, and autophagosomes were increased (P < 0.05). Besides, the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin signaling pathway, as a negative regulator of autophagy to some degree, was inhibited. This study revealed that vacuum therapy ameliorated pPED in BCNC rats by inhibiting apoptosis and activating autophagy.

N-acetylcysteine maintains penile length and erectile function in bilateral cavernous nerve crush rat model by reducing penile fibrosis.

Penile length shortening and erectile dysfunction are common complications after radical prostatectomy. Various methods have been used to maintain erectile function, but less attention has been paid to preserving penis length. N-acetylcysteine (NAC) has the effect of antioxidation and antifibrotic, which may be beneficial to improve those postoperative complications. This study investigated the effect of NAC on maintaining the penile length and the erectile function after bilateral cavernous nerve crush (BCNC) and its underlying mechanism. Twenty-four male rats were randomly divided into three groups: control group, BCNC group, and BCNC + NAC group. NAC or equal volume of saline was daily administrated by intragastric gavage for 4 weeks. The initial and end penile lengths were measured. Intracavernosal pressure/mean arterial pressure (ICP/MAP) ratio was calculated to assess erectile function. Hematoxylin-eosin staining, Masson's trichrome staining, immunohistochemistry, and Western blot were performed to explore cellular and molecular changes of the penis. Compared to the BCNC group, the penile length, ICP/MAP ratio and smooth muscle/collagen ratio in the BCNC + NAC group were improved significantly (all P < 0.05), and the expressions of endothelial nitric oxide synthase, α-smooth muscle actin, glutathione, and glutathione peroxidase 1 were significantly increased after NAC treated (all P < 0.05), along with the decreased expressions of hypoxia-inducible factor-1α, transforming growth factor-ß1, collagen I, collagen III, collagen IV, malonaldehyde, and lysine oxidase (all P < 0.05). This study demonstrated that NAC could maintain penile length and partly improve erectile function. Possible mechanism is directly and/or indirectly related to antihypoxic and antifibrosis.

Anti-lysyl oxidase combined with a vacuum device induces penile lengthening by remodeling the tunica albuginea.

This study aimed to explore whether and how anti-lysyl oxidase (anti-LOX) combined with a vacuum device (VD) could promote penile lengthening and to evaluate the effect on erectile function. This study was performed on four groups of adult rats: control, anti-LOX, VD (negative pressure value of -300 mmHg), and anti-LOX + VD. Penile length was measured by a modified VD method and verified on exposed length data. Intracavernous pressure (ICP) and maximum ICP/mean arterial pressure (MAP) ratio were recorded to assess erectile function. For corpus cavernosum, LOX activity and concentrations of pyridinoline, desmosine, hydroxyproline, and elastin were analyzed; transmission electron microscope and Hart's elastin staining were performed to monitor microstructural changes. Anti-LOX and VD significantly lengthened the penis by 10.8% (3.75 mm) and 8.2% (2.48 mm) compared with the control group, respectively, while anti-LOX + VD achieved the longest penile size (40.58 ± 0.40 mm) which was 17.4% longer than the control group (34.58 ± 0.54 mm). After 1-week washout, no penile retraction was observed. Meanwhile, exposed penile length data confirmed that the penis in the anti-LOX + VD group was also significantly longer. Anti-LOX inhibited LOX activity to reduce pyridinoline level, which led the penile tunica albuginea remodeling. However, it had no effect on hydroxyproline, desmosine, and elastin levels. Moreover, anti-LOX had no impact on erectile function, which was determined by ICP and ICP/MAP ratio. These results suggest that anti-LOX elongates the penis by reducing pyridinoline, which induces tunica albuginea remodeling. This lengthening effect was more obvious when combined with a VD. All procedures had no impact on erectile function.

Optimal pressure in penile rehabilitation with a vacuum erection device: evidence based on a rat model.

Vacuum erection device (VED), used to treat radical prostatectomy (RP)-associated erectile dysfunction, has attracted considerable attention. However, the optimal negative pressure remains to be determined. This investigation explored the optimal pressure for VED therapy in penile rehabilitation. Thirty-six 9-week-old male rats were randomly divided into six groups: control groups (sham group, bilateral cavernous nerve crush [BCNC] group) and VED therapy groups (-200 mmHg group, -300 mmHg group, -400 mmHg group, -500 mmHg group). BCNC group and VED therapy groups underwent BCNC surgery. Intracavernosal pressure (ICP)/mean arterial pressure (MAP) ratio was calculated to assess erectile function. Masson's trichrome (MT) staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, immunohistochemistry, and real-time polymerase chain reaction (RT-PCR) were performed to explore cellular and molecular changes of the penis. Compared to the BCNC group, ICP/MAP ratios in all VED treatment groups were improved significantly (all P < 0.05), but there were no statistically significant differences among VED therapy groups. With increased pressure, complications gradually emerged and increased in frequency. Expression of molecular indicators, such as endothelial nitric oxide synthase (eNOS) and alpha-smooth muscle actin (α-SMA), increased after VED therapy, and hypoxia-inducible factor 1α (HIF-1α) and transforming growth factor beta (TGF-ß) decreased. In addition, VED therapy improved the outcomes of MT and TUNEL assay. This investigation demonstrated a pressure of -200 mmHg in a rat model is optimal for VED therapy for penile rehabilitation after RP. No further benefits were observed with increased pressure, despite an increase in complications.

Two new polyketides isolated from a diethyl sulphate mutant of marine-derived Penicillium purpurogenum G59.

Two new polyketides, purpurofuranone (1) and purpuropyranone (2), were isolated along with the known polyketides, cillifuranone (3) and taiwapyrone (4), from a mutant BD-3n-1 derived from the diethyl sulfate (DES) mutagenesis of a marine-derived Penicillium purpurogenum G59. The structures of 1 and 2 were elucidated by spectroscopic methods especially on the basis of X-ray diffraction and calculated optical rotations data. The plausible biosynthesis of 1 - 4 was also proposed and discussed. In preliminary MTT assay, 1 - 4 showed no notable inhibitory effects on the tested four human cancer cell lines.

Terretonin D1, a new meroterpenoid from marine-derived Aspergillus terreus ML-44.

A new meroterpenoid, named terretonin D1 (1), and three known ones, terretonin (2), terretonin A (3), and terretonin D (4), were isolated from marine-derived fungus Aspergillus terreus ML-44. The structure of 1 was elucidated by extensive spectroscopic methods, including 1D and 2D NMR, HR-ESI-MS, and the absolute configuration was determined by X-ray crystallographic analysis. The anti-inflammation activity of 1-4 was preliminarily tested, and all of them weakly inhibited the nitric oxide (NO) production of RAW264.7 macrophages stimulated by lipopolysaccharide (LPS), with inhibitory rates of 22-34% at 50 µg/mL.

Meta-Analysis Results on the Association Between TP53 Codon 72 Polymorphism With the Susceptibility to Oral Cancer.

Objectives: TP53 is an important tumor suppressor gene to maintain genomic integrity, and its mutations increase the susceptibility to oral carcinoma. Previous published studies have reported the relation of TP53 codon 72 polymorphism with the risk of oral carcinoma, but the results remain controversial and inconclusive. Methods: We therefore utilized meta-analysis based on a comprehensive search in PubMed, EMBASE, and Google of Scholar databases up to August 19, 2017. Results: Total 3,525 cases and 3,712 controls from 21 case-control studies were selected. We found no significant association between TP53 codon 72 polymorphism and oral carcinoma susceptibility in all genetic contrast models, including subgroup analysis based on control source and ethnicity. Furthermore, TP53 codon 72 polymorphism was not significant associated with oral carcinoma susceptibility in tobacco or alcohol use, and HPV infection status. Our results were confirmed by sensitivity analysis and no publication bias was found. Conclusions: Taken together, our data indicate that TP53 codon 72 polymorphism is not associated with the susceptibility to oral carcinoma.

Association between IL-4 and IL-4R Polymorphisms and Periodontitis: A Meta-Analysis.

Background. Previous studies have revealed that gene polymorphisms of inflammatory factors may influence the development or progression of periodontitis, a main cause of tooth loss in adults; however, due to limitations of individual studies, inconsistent findings were reported. Objective. To meta-analytically investigate the relationship between periodontitis and the Interleukin-4 (IL-4) and Interleukin-4 receptor (IL-4R) gene polymorphisms. Methods. Databases were searched for relevant case-control studies. After study selection based on the predefined selection criteria, methodological quality assessment and data extraction were conducted independently by two reviewers, before subsequent statistical analyses. Results. 37 studies involving 4,385 patients and 5,168 controls were included. All the studied IL-4 polymorphisms were not significantly associated with periodontitis, except the -33C/T (CT versus CC: OR = 0.50, 95% CI = 0.28-0.88) associated with reduced AgP susceptibility. Positive association was found between IL-4R Q551 polymorphism and periodontitis susceptibility in three genetic models (R versus Q: OR = 1.59, 95% CI = 1.14-2.22; QR versus QQ: OR = 1.84, 95% CI = 1.21-2.80; RR + QR versus QQ: OR = 1.82, 95% CI = 1.22-2.72). Conclusions. A positive association exists between the IL-4R Q551R polymorphism and occurrence of CP. The IL-4 -33 CT genotype is negatively associated with the occurrence of AgP.

Leucine-derived cyanoglucosides from the aerial parts of Sorbaria sorbifolia (L.) A. Braun.

Six new cyanoglucosides, 2S-cardiospermin-5-benzoate (1), 2R-cardiospermin-5-p-hydroxybenzoate (2), 2S-cardiospermin-5-cis-p-coumarate (3), isocardiospermin-5-p-hydroxybenzoate (4), sutherlandin-5-p-hydroxybenzoate (5), and sutherlandin-5-cis-p-coumarate (6), together with 17 known compounds were isolated from Sorbaria sorbifolia. The structures of the new compounds were elucidated by extensive spectroscopic methods, including 1D and 2D NMR, HR-ESI-MS and ECD experiments. The biosynthetic relationship of 1-9 was also discussed. The cyanoglucosides (1-9) and 15 exhibited moderate inhibitory effect on nitric oxide production of RAW264.7 macrophages stimulated by lipopolysaccharide (LPS).

Rare Chromones from a Fungal Mutant of the Marine-Derived Penicillium purpurogenum G59.

Three new and rare chromones, named epiremisporine B (2), epiremisporine B1 (3) and isoconiochaetone C (4), along with three known remisporine B (1), coniochaetone A (5) and methyl 8-hydroxy-6-methyl-9-oxo-9H-xanthene-1-carboxylate (6) were isolated from a mutant from the diethyl sulfate (DES) mutagenesis of a marine-derived Penicillium purpurogenum G59. The structures of 2-4 including the absolute configurations were determined by spectroscopic methods, especially by NMR analysis and electronic circular dichroism (ECD) experiments in conjunction with calculations. The absolute configuration of the known remisporine B (1) was determined for the first time. Compounds 2 and 3 have a rare feature that has only been reported in one example so far. The compounds 1-6 were evaluated for their cytotoxicity against several human cancer cell lines. The present work explored the great potential of our previous DES mutagenesis strategy for activating silent fungal pathways, which has accelerated the discovery of new bioactive compounds.

Activation of the silent secondary metabolite production by introducing neomycin-resistance in a marine-derived Penicillium purpurogenum G59.

Introduction of neomycin-resistance into a marine-derived, wild-type Penicillium purpurogenum G59 resulted in activation of silent biosynthetic pathways for the secondary metabolite production. Upon treatment of G59 spores with neomycin and dimethyl sulfoxide (DMSO), a total of 56 mutants were obtained by single colony isolation. The acquired resistance of mutants to neomycin was testified by the resistance test. In contrast to the G59 strain, the EtOAc extracts of 28 mutants inhibited the human cancer K562 cells, indicating that the 28 mutants have acquired the capability to produce bioactive metabolites. HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses further indicated that diverse secondary metabolites have been newly produced in the bioactive mutant extracts. Followed isolation and characterization demonstrated that five bioactive secondary metabolites, curvularin (1), citrinin (2), penicitrinone A (3), erythro-23-O-methylneocyclocitrinol (4) and 22E-7α-methoxy-5α, 6α-epoxyergosta-8(14),22-dien-3ß-ol (5), were newly produced by a mutant, 4-30, compared to the G59 strain. All 1-5 were also not yet found in the secondary metabolites of other wild type P. purpurogenum strains. Compounds 1-5 inhibited human cancer K562, HL-60, HeLa and BGC-823 cells to varying extents. Both present bioassays and chemical investigations demonstrated that the introduction of neomycin-resistance into the marine-derived fungal G59 strain could activate silent secondary metabolite production. The present work not only extended the previous DMSO-mediated method for introducing drug-resistance in fungi both in DMSO concentrations and antibiotics, but also additionally exemplified effectiveness of this method for activating silent fungal secondary metabolites. This method could be applied to other fungal isolates to elicit their metabolic potentials to investigate secondary metabolites from silent biosynthetic pathways.

Activation of dormant secondary metabolite production by introducing neomycin resistance into the deep-sea fungus, Aspergillus versicolor ZBY-3.

A new ultrasound-mediated approach has been developed to introduce neomycin-resistance to activate silent pathways for secondary metabolite production in a bio-inactive, deep-sea fungus, Aspergillus versicolor ZBY-3. Upon treatment of the ZBY-3 spores with a high concentration of neomycin by proper ultrasound irradiation, a total of 30 mutants were obtained by single colony isolation. The acquired resistance of the mutants to neomycin was confirmed by a resistance test. In contrast to the ZBY-3 strain, the EtOAc extracts of 22 of the 30 mutants inhibited the human cancer K562 cells, indicating that these mutants acquired a capability to produce antitumor metabolites. HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses of the EtOAc extracts of seven bioactive mutants and the ZBY-3 strain indicated that diverse secondary metabolites have been newly produced in the mutant extracts in contrast to the ZBY-3 extract. The followed isolation and characterization demonstrated that six metabolites, cyclo(D-Pro-D-Phe) (1), cyclo(D-Tyr-D-Pro) (2), phenethyl 5-oxo-L-prolinate (3), cyclo(L-Ile-L-Pro) (4), cyclo(L-Leu-L-Pro) (5) and 3ß,5α,9α-trihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (6), were newly produced by the mutant u2n2h3-3 compared to the parent ZBY-3 strain. Compound 3 was a new compound; 2 was isolated from a natural source for the first time, and all of these compounds were also not yet found in the metabolites of other A. versicolor strains. Compounds 1-6 inhibited the K562 cells, with inhibition rates of 54.6% (1), 72.9% (2), 23.5% (3), 29.6% (4), 30.9% (5) and 51.1% (6) at 100 µg/mL, and inhibited also other human cancer HL-60, BGC-823 and HeLa cells, to some extent. The present study demonstrated the effectiveness of the ultrasound-mediated approach to activate silent metabolite production in fungi by introducing acquired resistance to aminoglycosides and its potential for discovering new compounds from silent fungal metabolic pathways. This approach could be applied to elicit the metabolic potentials of other fungal isolates to discover new compounds from cryptic secondary metabolites.

A practical strategy to discover new antitumor compounds by activating silent metabolite production in fungi by diethyl sulphate mutagenesis.

Many fungal biosynthetic pathways are silent in standard culture conditions, and activation of the silent pathways may enable access to new metabolites with antitumor activities. The aim of the present study was to develop a practical strategy for microbial chemists to access silent metabolites in fungi. We demonstrated this strategy using a marine-derived fungus Penicillium purpurogenum G59 and a modified diethyl sulphate mutagenesis procedure. Using this strategy, we discovered four new antitumor compounds named penicimutanolone (1), penicimutanin A (2), penicimutanin B (3), and penicimutatin (4). Structures of the new compounds were elucidated by spectroscopic methods, especially extensive 2D NMR analysis. Antitumor activities were assayed by the MTT method using human cancer cell lines. Bioassays and HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses were used to estimate the activated secondary metabolite production. Compounds 2 and 3 had novel structures, and 1 was a new compound belonging to a class of very rare natural products from which only four members are so far known. Compounds 1-3 inhibited several human cancer cell lines with IC50 values lower than 20 µM, and 4 inhibited the cell lines to some extent. These results demonstrated the effectiveness of this strategy to discover new compounds by activating silent fungal metabolic pathways. These discoveries provide rationale for the increased use of chemical mutagenesis strategies in silent fungal metabolite studies.

Seven new and two known lipopeptides as well as five known polyketides: the activated production of silent metabolites in a marine-derived fungus by chemical mutagenesis strategy using diethyl sulphate.

AD-2-1 is an antitumor fungal mutant obtained by diethyl sulfate mutagenesis of a marine-derived Penicillium purpurogenum G59. The G59 strain originally did not produce any metabolites with antitumor activities in MTT assays using K562 cells. Tracing newly produced metabolites under guidance of MTT assay and TLC analysis by direct comparison with control G59 extract, seven new (1-7) and two known (8-9) lipopeptides were isolated together with five known polyketides 10-14 from the extract of mutant AD-2-1. Structures of the seven new compounds including their absolute configurations were determined by spectroscopic and chemical evidences and named as penicimutalides A-G (1-7). Seven known compounds were identified as fellutamide B (8), fellutamide C (9), 1'-O-methylaverantin (10), averantin (11), averufin (12), nidurufin (13), and sterigmatocystin (14). In the MTT assay, 1-14 inhibited several human cancer cell lines to varying extents. All the bioassays and HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses demonstrated that the production of 1-14 in the mutant AD-2-1 was caused by the activated production of silent metabolites in the original G59 fungal strain. Present results provided additional examples for effectiveness of the chemical mutagenesis strategy using diethyl sulphate mutagenesis to discover new compounds by activating silent metabolites in fungal isolates.

Three new and eleven known unusual C25 steroids: activated production of silent metabolites in a marine-derived fungus by chemical mutagenesis strategy using diethyl sulphate.

Three new (1-3) and 11 known (4-14) C25 steroids with an unusual bicyclo[4.4.1]A/B ring system were isolated by tracing newly produced metabolites in the EtOAc extract of an antitumor mutant AD-1-2 obtained by the diethyl sulphate (DES) mutagenesis of a marine-derived Penicillium purpurogenum G59. HPLC-PDAD-UV and HPLC-ESI-MS analyses indicated that the G59 strain did not produce these metabolites and the production of 1-14 in the mutant AD-1-2 extract was caused by the activation of silent metabolites in the original G59 strain by DES mutagenesis. The structures of the new compounds, named antineocyclocitrinols A (1) and B (2) and 23-O-methylantineocyclocitrinol (3), including their absolute configurations were determined by various spectroscopic methods, especially the NMR and Mo2-induced CD analyses. Compounds 1-3 provide the first examples of the C25 bicyclo[4.4.1]A/B ring steroids with the Z-configuration of 20,22-double bond. All of 1-14 weakly inhibited several human cancer cell lines to varying extents. These results provided additional examples for the successful application of the chemical mutagenesis strategy using DES to discover new compounds by activating silent metabolites in fungal isolates and supported also the effectiveness and usefulness of this new strategy.

Purpurogemutantin and purpurogemutantidin, new drimenyl cyclohexenone derivatives produced by a mutant obtained by diethyl sulfate mutagenesis of a marine-derived Penicillium purpurogenum G59.

Two new drimenyl cyclohexenone derivatives, named purpurogemutantin (1) and purpurogemutantidin (2), and the known macrophorin A (3) were isolated from a bioactive mutant BD-1-6 obtained by random diethyl sulfate (DES) mutagenesis of a marine-derived Penicillium purpurogenum G59. Structures and absolute configurations of 1 and 2 were determined by extensive spectroscopic methods, especially 2D NMR and electronic circular dichroism (ECD) analysis. Possible biosynthetic pathways for 1-3 were also proposed and discussed. Compounds 1 and 2 significantly inhibited human cancer K562, HL-60, HeLa, BGC-823 and MCF-7 cells, and compound 3 also inhibited the K562 and HL-60 cells. Both bioassay and chemical analysis (HPLC, LC-ESIMS) demonstrated that the parent strain G59 did not produce 1-3, and that DES-induced mutation(s) in the mutant BD-1-6 activated some silent biosynthetic pathways in the parent strain G59, including one set for 1-3 production.

Activation of the dormant secondary metabolite production by introducing gentamicin-resistance in a marine-derived Penicillium purpurogenum G59.

A new approach to activate silent gene clusters for dormant secondary metabolite production has been developed by introducing gentamicin-resistance to an originally inactive, marine-derived fungal strain Penicillium purpurogenum G59. Upon treatment of the G59 spores with a high concentration of gentamicin in aqueous DMSO, a total of 181 mutants were obtained by single colony isolation. In contrast to the strain G59, the EtOAc extracts of nine mutant cultures showed inhibitory effects on K562 cells, indicating that the nine mutants had acquired capability to produce antitumor metabolites. This was evidenced by TLC and HPLC analysis of EtOAc extracts of G59 and the nine mutants. Further isolation and characterization demonstrated that four antitumor secondary metabolites, janthinone (1), fructigenine A (2), aspterric acid methyl ester (3) and citrinin (4), were newly produced by mutant 5-1-4 compared to the parent strain G59, and which were also not found in the secondary metabolites of other Penicillium purpurogenum strains. However, Compounds 1-4 inhibited the proliferation of K562 cells with inhibition rates of 34.6% (1), 60.8% (2), 31.7% (3) and 67.1% (4) at 100 µg/mL, respectively. The present study demonstrated the effectiveness of a simple, yet practical approach to activate the production of dormant fungal secondary metabolites by introducing acquired resistance to aminoglycoside antibiotics, which could be applied to the studies for eliciting dormant metabolic potential of fungi to obtain cryptic secondary metabolites.

[Effect of cytoskeleton integrity on the expression of c-fos in osteoblasts induced by fluid shear stress].

OBJECTIVE: To investigate the effect of cytoskeleton integrity on the expression of c-fos gene in osteoblasts induced by fluid shear stress. METHODS: BALB/c mouse primary osteoblasts were divided into four groups (according to fluid shear stress loaded or not and cytochalasin D used or not). The Tagman probe real-time PCR and immunofluorescence were performed to detect the expression levels of c-fos mRNA, c-fos protein and cytoskeleton, respectively. The data were analysed using two-way ANOVA. RESULTS: In control group and cytochalasin D group, fluid shear stress could significantly increase the expression levels of c-fos mRNA (0.1637 +/- 0.0303 and 0.0104 +/- 0.0070, respectively) and protein (177.14 +/- 9.37 and 150.95 +/- 6.17, respectively) in osteoblasts, compared with the unloaded osteoblasts of the control group and the cytochalasin D group (0.0057 +/- 0.0021 and 0.0032 +/- 0.0014, respectively for c-fos mRNA, and 117.96 +/- 4.11 and 119.77 +/- 5.19, respectively for protein, P < 0.05). Induced by the fluid shear stress, the expression levels of c-fos mRNA and protein in cytochalasin D group were lower than control group, and the difference had statistical significance (P < 0.05). CONCLUSIONS: The cytoskeleton integrity in osteoblasts was essential to the expression of c-fos gene induced by fluid shear stress.

[Effects of LIMK2 RNA interference on the mechanosensitivity of c-fos gene in osteoblast].

OBJECTIVE: To study the effects of cytoskeleton reorganization inhibition with LIMK2 RNAi upon the mechanosensitivity of c-fos gene in osteoblast. METHODS: Mouse primary osteoblast was treated with LIMK2 specific siRNA (RNAi Group), negative control siRNA (NC Group), and then were loaded or unloaded by fluid shear stress. Real-time PCR and immunofluorescence were used to detect the c-fos expression levels and statistics analysis was performed. RESULTS: When the cytoskeleton reorganization was inhibited with RNAi only, the c-fos mRNA (0.0108 +/- 0.0074 and 0.0042 +/- 0.0018, t = -1.86, P > 0.05) and protein (121 +/- 7 and 119 +/- 6, t = -1.272, P > 0.05) expression levels of each unloaded group had no significant difference; Fluid shear stress could up-regulate the c-fos mRNA (0.2203 +/- 0.1532 vs 0.0042 +/- 0.0018, t = -707.35, P < 0.05)and protein (178 +/- 12 vs 119 +/- 6, t = -30.761, P < 0.05) expression; After the cytoskeleton reorganization was inhibited with RNAi, the c-fos mRNA (0.5280 +/- 0.0879 vs 0.2203 +/- 0.1532, t = -1007.00, P < 0.05) and protein (224 +/- 46 vs 178 +/- 12, t = -6.853, P < 0.05) expression induced by fluid shear stress had significant difference. Cytoskeleton reorganization inhibition with RNAi had synergistic effect upon the expression of c-fos mRNA (F = 84.388, P < 0.05) and protein (F = 42.409, P < 0.05) induced by fluid shear stress. CONCLUSION: Using RNAi against LIMK2 to inhibit the cytoskeleton reorganization can promote the expression of c-fos gene and thus enhance the mechanosensitivity of c-fos gene in osteoblast.