[Role of CMKLR1 on mouse vascular smooth muscle cells proliferation and related mechanism]

OBJECTIVE

To explore the proliferation property of vascular smooth muscle cells (VSMCs) in the stable CMKLR1 gene knock-down mouse VSMCs line and explore related mechanism.

METHODS

The short hairpin RNA sequence targeting to knockdown the coding regions of mouse CMKLR1 mRNA was synthesized and subsequently employed to construct recombinant lentivirus vector.Mouse VSMCs were cultured and infected with the recombinant lentivirus (knockdown VSMCs). mRNA and protein CMKLR1 expression in Knockdown VSMCs was measured by real-time PCR and Western blot and compared with those in normal VSMCs (vehicle VSMCs) and lentivirus control VSMCs (control VSMCs). The proliferation of normal, knockdown and control VSMCs was induced by platelet-derived growth factor-BB (PDGF VSMCs) and measured by cell number counting and BrdU.The phosphorylated c-Jun N-terminal kinase (p-JNK) protein was investigated by Western blot.

RESULTS

The relative level of CMKLR1 mRNA in knockdown VSMCs (0.23±0.04) was significantly downregulated compared with which in vehicle VSMCs (1.05±0.05) as well as control VSMCs (0.99±0.04) (P<0.01). The relative level of CMKLR1 protein in knockdown VSMCs (0.29±0.04) was also significantly decreased, compared with which in vehicle VSMCs (1.06±0.04) as well as control VSMCs (0.95±0.02) (P<0.01). The VSMCs number ((50.33±1.20)×10(3)/cm(2)) and BrdU A450 nm value (1.80±0.05) in PDGF VSMCs were significantly increased in vehicle VSMCs ((42.02±1.53)×10(3)/cm(2,) 1.55±0.04) (both P<0.05). Compared with those in vehicle VSMCs, the VSMCs number ((23.33±2.03)×10(3)/cm(2)) and BrdU A450 nm value (1.32±0.02) in knockdown VSMCs were significantly decreased.The proliferation property between PDGF VSMCs and control VSMCs was similar(P>0.05). Compared with the relative level of p-JNK protein (1.03±0.03) in vehicle VSMCs, the p-JNK protein level was significantly increased in PDGF VSMCs (1.36±0.02, P<0.05) and significantly downregulated in knockdown VSMCs (0.79±0.05, P<0.05).

CONCLUSION

Knockdowning CMKLR1 gene can reduce the proliferation of mouse vascular smooth muscle cells, which was related with the down-regulation of p-JNK expression.

Regulation of size and uniformity of In2O3 nanooctahedra

Rational regulation of the size and uniformity of nanoparticles has drawn great interests and shown widespread application, but this cannot be simply achieved by the vapor route. In this work, by adopting a chemical vapor deposition approach, the growth process was intricately regulated to guide the reagent supersaturation, and the large-scale growth of uniform-sized In2O3 nanooctahedra was realized. A one-time nucleation and synchronous growth mode controlled by the reagent supersaturation ratio is proposed to be responsible for the uniformity of size. Furthermore, a series of comparative experiments were conducted to study the size dependence on reaction duration, and temperature difference between the heating and depositing zones. This study demonstrates a feasible approach to prepare uniform-sized nanoparticles through precisely controlling the crystal growth process, and the developed growth strategy could be generalized to synthesize uniform-sized nanostructures of other material systems.

miR-141 is involved in BRD7-mediated cell proliferation and tumor formation through suppression of the PTEN/AKT pathway in nasopharyngeal carcinoma

Bromodomain containing 7 (BRD7) was identified as a nuclear transcriptional regulatory factor. BRD7 functions as a tumor suppressor in multiple cancers, including nasopharyngeal carcinoma (NPC). In this study, we reported a novel mechanism of BRD7 in NPC progression. We demonstrated that the expression of miR-141 was remarkably increased in NPC tissues and was negatively correlated with the expression of BRD7 and the survival rate of NPC patients. Decreased expression levels of miR-141, including the primary, the precursor and the mature forms of miR-141, were found in BRD7-overexpressing HEK293, 5-8F and HNE1 cells compared the control cells, while there was no obvious effect on the expression levels of the two critical enzymes Drosha and Dicer. BRD7 can negatively regulate the promoter activity of miR-141, while no obvious binding site of BRD7 was found in the potential promoter region of miR-141. Moreover, ectopic expression of miR-141 can significantly promote cell proliferation and inhibit apoptosis in NPC, and rescuing the expression of miR-141 in BRD7-overexpressing NPC cells could partially reverse the tumor suppressive effect of BRD7 on cell proliferation and tumor growth in vitro and in vivo. Furthermore, the activation of the PTEN/AKT pathway mediated by the overexpression of BRD7 could be inhibited by rescuing the expression of miR-141, which accordingly results in the partial restoration of cell proliferation and tumor growth. Our findings demonstrate that the BRD7/miR-141/PTEN/AKT axis has critical roles in the progression of NPC and provide some promising targets for the diagnosis and treatment of NPC.

An let-7 KRAS rs712 polymorphism increases hepatocellular carcinoma risk

KRAS, also known as V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog, acts as an intracellular signal transducer. The oncogenic KRAS mutation is an essential step in the development of many types of human cancers, including hepatocellular carcinoma. Here we aimed to investigate the relationship between KRAS rs712 polymorphisms and hepatocellular carcinoma susceptibility. Five-hundred-and-fourteen participants were enrolled in a case-control study (262 cases and 252 normal subjects). The variants were distinguished using polymerase chain reaction-restriction fragment length polymorphism. Significantly increased HCC risk was observed to be associated with the T allele of the rs712 locus (P = 0.049, OR = 1.35, 95%CI = 1.01-1.78). Further, HCC risk with the GT genotype (P = 0.015, OR = 1.64, 95%CI = 1.08-2.50) and the TT genotype (P = 0.015, OR = 2.56, 95%CI = 1.05-6.25) in a codominant model was significantly higher than that with the GG genotype. In a dominant model, significantly increased HCC susceptibility was also associated with T allele carriers (P = 0.006, OR = 1.75, 95%CI = 1.16-2.63). Moreover, we found that the frequency of the KRAS rs712 TT genotype was significantly higher in HBV-positive HCC patients than in HBV-negative HCC patients.

Regulation of the expression of zinc finger protein genes by microRNAs enriched within acute lymphoblastic leukemia-derived microvesicles

Microvesicles (MVs) are submicrometric membrane fragments that can "engulf" cytoplasmic contents such as microRNAs (miRNAs) from their cellular origin. The study of miRNAs carried within MVs might provide insights into the roles that miRNAs play in the underlying pathophysiologic processes of acute lymphoblastic leu-kemia (ALL). We identified numerous dysregulated MV miRNAs in patients with B- and T-cell ALL by using Agilent microarray analysis. Selected miRNAs obtained by microarray profiling were validated us-ing quantitative reverse transcription-polymerase chain reaction. Us-ing bioinformatic tools, we found that 118 and 116 miRNAs from B- and T-ALL MVs, respectively, regulated the expression of zinc finger protein (ZFP) genes. For example, zinc finger protein 238 (ZNF238), known as a tumor suppressor, was regulated by miR-20b over-expres-sion. Conversely, ZNF267, a cancer-promoting factor, was mediated by downregulated miR-23a and miR-23b. Considering that miRNAs are generally believed to repress gene expression, antineoplastic ZNF238 was likely inhibited while the level of oncogenic ZNF267 was likely increased by miRNA dysregulation, leading to modifica-tion of the ALL microenvironment. In addition, gene ontology and sig-naling pathway analysis demonstrated that a subset of the ZFP genes targeted by altered MV miRNAs are involved in cellular biological processes including proliferation, differentiation, apoptosis, and cell cycle regulation. These findings indicated that cancer-associated MV miRNAs and their target ZFP genes might be novel pathogenic factors in ALL. However, the specific roles exerted by MV miRNAs and their target ZFP genes on the pathological mechanisms of ALL remain to be further understood.

A randomized clinical trial of the effects of ultra-low-dose naloxone infusion on postoperative opioid requirements and recovery

BACKGROUND

Tolerance to remifentanil during sevoflurane anesthesia may increase postoperative analgesic requirements. Low-dose naloxone not only has been shown to block the development of acute opioid tolerance but also to ameliorate undesired opioid-induced side effects. We hypothesized that naloxone prevents the acute opioid tolerance produced by a large dose of remifentanil, and reduces the incidence of opioid-induced side effects.

METHODS

Seventy-two patients undergoing open colorectal surgery were randomly assigned to receive intraoperative remifentanil (1) small dose at 0.1 μg/kg/min; (2) large dose at 0.30 μg/kg/min; or (3) large dose at 0.30 μg/kg/min combined with low-dose naloxone at 0.25 μg/kg/h just after the induction. Cumulative morphine consumption, postoperative pain scores, incidence of opioid-related side effects, time to recovery of bowel function, and length of hospital stay were recorded.

RESULTS

Cumulative morphine consumption at 24 h after surgery was higher in the large-dose remifentanil group (28 ± 12 mg) compared with the small-dose remifentanil group (17 ± 12 mg), and large-dose remifentanil-naloxone group (18 ± 9 mg), (P < 0.001). The median time to return of bowel function was shorter in the large-dose remifentanil-naloxone group than the other two groups (P < 0.05). The median length of hospital stay was lower in the large-dose remifentanil-naloxone group (8 [interquartile range: 8-12] days) compared with the small-dose remifentanil group (12 [interquartile range: 9-15] days) and large-dose remifentanil group (12 [interquartile range: 10-13] days), (P < 0.001).

CONCLUSION

Naloxone infusion prevented the acute opioid tolerance, provided a quicker recovery of bowel function, and reduced the length of hospital stay after open colorectal surgery.

Suppression of Inflammatory Responses by Dihydromyricetin, a Flavonoid from Ampelopsis grossedentata, via Inhibiting the Activation of NF-κB and MAPK Signaling Pathways

Ampelopsis grossedentata, an indigenous plant in southern China, has been used for treating pharyngitis in traditional Chinese medicine for hundreds of years. In this study, we explored the anti-inflammatory activity of dihydromyricetin (1), its major bioactive component, and the underlying mechanism of this action. We demonstrated that 1 suppressed the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) as well as increased the level of the anti-inflammatory cytokine interleukin-10 (IL-10) in lipopolysaccharide (LPS)-treated mice. Moreover, 1 was found to markedly inhibit the production of nitric oxide (NO) and the levels of TNF-α, IL-1β, and IL-6, whereas it increased the level of IL-10 in LPS-induced RAW 264.7 macrophage cells. Compound 1 also reduced the protein expression of inducible nitric oxide synthase (iNOS), TNF-α, and cyclooxygenase-2 (COX-2) in macrophage cells. Furthermore, 1 suppressed the phosphorylation of NF-kappa B (NF-κB) and IκBα as well as the phosphorylation of p38 and JNK but not ERK1/2 in LPS-stimulated macrophages. Taken together, the present results suggest that 1 exerts its topical anti-inflammatory action through suppressing the activation of NF-κB and the phosphorylation of p38 and JNK. Thus, 1 may be a potentially useful therapeutic agent for inflammatory-related diseases.

Closing the knowledge gap in secondhand smoke exposure among children: employment of a five-minute household survey in China

OBJECTIVE

The 2010 Global Burden of Disease study unexpectedly reports no health burden associated with secondhand smoke (SHS) exposure in children 5-17 years of age. One possible reason for this error is that children under 13 years of age are not considered in standard community surveys of SHS exposure. This study aims to use a 5-min household survey to estimate the prevalence of SHS exposure among children in urban and rural China.

STUDY DESIGN

Cross-sectional survey.

METHODS

A multi-stage stratified sample of 1120 urban and rural households with 3073 residents from the Ningbo, China, was identified and one adult member from each household was administered a brief survey about the demographic characteristics and smoking status of all household residents.

RESULTS

Adjusting for the sampling design and clustering within households, 63% of children less than 7 years of age, 53% of the children 7-12 years of age, and 54% of the children 13-17 years of age were living in households with daily smokers. Controlling for the number of male residents, significantly more households with daily smokers were located in rural areas (p < 0.001) and the average education level of adults in households with daily smokers was significantly lower than that among adults in households without daily smokers (p = 0.007).

CONCLUSION

The heavy household exposure of children in China to SHS is an unrecognized public health problem that demands urgent policy and programmatic responses. The brief household survey developed for this study is an easy method for monitoring the prevalence of SHS exposure of children over time that could be useful in community-based tobacco control initiatives.

Mesenchymal stem cell-based FGF2 gene therapy for acute lung injury induced by lipopolysaccharide in mice

OBJECTIVE

Bone marrow-derived mesenchymal stem cells (MSCs) can serve as a vehicle for gene therapy. FGF2 (basic fibroblast growth factor) is a multifunctional growth factor and exhibits diverse function in different cell types, it also has pleiotropic effects in different tissues and organs, including potent angiogenic effects and an important role in the differentiation and function of the central nervous system. We hypothesized that MSC-based FGF2 gene therapy might be a potential therapeutic approach for lipopolysaccharide (LPS)-induced lung injury.

MATERIALS AND METHODS

MSCs were isolated from 6 week-old inbred male mice and transduced with the FGF2 gene, using a lentivirus vector.

RESULTS

In the in vivo mouse model, the LPS-induced lung injury was markedly alleviated in the group treated with MSCs carrying FGF2 (MSCs-FGF2), compared with groups treated with MSCs alone. The histopathological index of LPS-induced lung injury was improved after MSCs-based FGF2 gene treatment. The MSCs-FGF2 administration also reduced the level of inflammatory cytokines.

CONCLUSIONS

These results suggest that MSCs and FGF2 have a synergistic role in the treatment of LPS-induced lung injury.

Solid-state graphene formation via a nickel carbide intermediate phase

Direct formation of graphene with a controlled number of graphitic layers on dielectric surfaces is achieved with an in-depth understanding of the solid-state growth mechanism.

Mass spectrometric investigation of the roles of several chemical intermediates in diamond synthesis

Mass spectrometric studies were performed to investigate several key chemical intermediates and identify their roles in diamond synthesis in a C₂H₄/C₂H₂/O₂ combustion-flame chemical vapour deposition process.

Contrast enhancement using silica microspheres in coherent anti-Stokes Raman spectroscopic imaging

Coherent anti-Stokes Raman scattering (CARS) microscopy is a powerful imaging technique that can provide chemical information of organic and nonorganic materials through vibrational spectroscopy. However, its contrast is not sufficient for monitoring thin film materials. In this study, silica microspheres were employed for enhancing the signal contrast in CARS imaging. One layer of optically transparent silica microspheres was self-assembled onto polymer grating samples to enhance the CARS signals. The highest contrast enhancement factor of 12.5 was achieved using 6.1-μm-diameter microspheres. Finite-difference time-domain method (FDTD) simulation was conducted to simulate the contrast enhancement with silica microspheres of different diameters.

Multiple amino acid mutations in viral RNA polymerase may synergistically enhance the transmissibility and/or virulence of the 2009 pandemic influenza (H1N1) virus

Influenza viruses may change their transmissibility and virulence via single or multiple point mutations in the functional regions of their structural proteins. In this study, we compared sequences of all three subunits of viral RNA polymerase, i.e. PA, PB1 and PB2, of the 2009 pandemic influenza A (H1N1) virus isolates from different stages of the pandemic and found that the frequencies of three mutations, including V14I and K716Q in PA and K736G in PB1, showed a similar trend. Interestingly, the death rate of infected patients during the pandemic matched the frequency of the three mutations with a 2-months delay. These findings suggest that the combined mutations may have acted synergistically in enhancing the transmissibility and/or virulence of the 2009 pandemic virus. If definitely proved, this hypothesis could guide the rational design of antiviral therapeutics targeting the RNA polymerase of influenza viruses.