108 m Underwater Wireless Optical Communication Using a 490 nm Blue VECSEL and an AOM.

Advanced light sources in the blue-green band are crucial for underwater wireless optical communication (UWOC) systems. Vertical-external-cavity surface-emitting lasers (VECSELs) can produce high output power and good beam quality, making them suitable for UWOC. This paper presents a 108 m distance UWOC based on a 100 mW 490 nm blue VECSEL and an acousto-optic modulator (AOM). The high-quality beam, which is near diffraction-limited, undergoes relatively small optical attenuation when using a conventional avalanche photodiode (APD) as the detector and employing 64-pulse position modulation (PPM). At the time-slot frequency of 50 MHz, the bit error rate (BER) of the UWOC was 2.7 × 10-5. This is the first reported AOM-based UWOC system with a transmission distance over 100 m. The estimated maximum transmission distance may be improved to about 180 m by fully utilizing the detection accuracy of the APD according to the measured attenuation coefficient of the blue VECSEL used. This type of UWOC system, composed of a high-beam-quality light source and a conventional detector, make it more closely suited to practical applications.

PLIN5 Suppresses Lipotoxicity and Ferroptosis in Cardiomyocyte via Modulating PIR/NF-κB Axis.

Cardiomyocyte lipotoxicity and ferroptosis are the key to the development of diabetic cardiomyopathy (DCM). Perilipin 5 (PLIN5) is perceived as a significant target of DCM. This study aimed to focus on the role and mechanism of PLIN5 on lipotoxicity and ferroptosis in DCM.Following transfection, mouse cardiomyocytes HL-1 were induced by 0.1 mM palmitic acid (PA) to set up lipotoxic cardiomyocyte models. The cell viability and lipid accumulation were evaluated by cell counting kit-8 assay and Oil red O staining, respectively. Ferrous ion (Fe2+), glutathione (GSH), malondialdehyde (MDA), and reactive oxygen species (ROS) levels were determined to verify the effects of PLIN5 or Pirin (PIR) on ferroptosis. Quantitative real-time reverse transcription polymerase chain reaction or Western blot was performed for quantitative analysis.PLIN5 overexpression promoted the viability, GSH level, and expression of GPX4/PIR/intracellular P65, yet suppressed lipid accumulation, level of Fe2+/MDA/ROS, and expression of interleukin (IL)-1ß/IL-18/intranuclear P65 in PA-stimulated HL-1 cells. PIR silencing counteracted the roles of PLIN5 overexpression in PA-stimulated HL-1 cells.PLIN5 suppresses lipotoxicity and ferroptosis in cardiomyocyte via modulating PIR/NF-κB axis, hinting its potential as a therapeutic target in DCM.

Solvent Engineering of Oxygen-Enriched Carbon Dots for Efficient Electrochemical Hydrogen Peroxide Production.

The development of cost-effective and reliable metal-free carbon-based electrocatalysts has gained significant attention for electrochemical hydrogen peroxide (H2 O2 ) generation through a two-electron oxygen reduction reaction. In this study, a scalable solvent engineering strategy is employed to fabricate oxygen-doped carbon dots (O-CDs) that exhibit excellent performance as electrocatalysts. By adjusting the ratio of ethanol and acetone solvents during the synthesis, the surface electronic structure of the resulting O-CDs can be systematically tuned. The amount of edge active CO group was strongly correlated with the selectivity and activity of the O-CDs. The optimum O-CDs-3 exhibited extraordinary H2 O2 selectivity of up to 96.55% (n = 2.06) at 0.65 V (vs RHE) and achieved a remarkably low Tafel plot of 64.8 mV dec-1 . Furthermore, the realistic H2 O2 productivity yield of flow cell is measured to be as high as 111.18 mg h-1  cm-2 for a duration of 10 h. The findings highlight the potential of universal solvent engineering approach for enabling the development of carbon-based electrocatalytic materials with improved performance. Further studies will be undertaken to explore the practical implications of the findings for advancing the field of carbon-based electrocatalysis.

Protein acetylation and related potential therapeutic strategies in kidney disease.

Kidney disease can be caused by various internal and external factors that have led to a continual increase in global deaths. Current treatment methods can alleviate but do not markedly prevent disease development. Further research on kidney disease has revealed the crucial function of epigenetics, especially acetylation, in the pathology and physiology of the kidney. Histone acetyltransferases (HATs), histone deacetylases (HDACs), and acetyllysine readers jointly regulate acetylation, thus affecting kidney physiological homoeostasis. Recent studies have shown that acetylation improves mechanisms and pathways involved in various types of nephropathy. The discovery and application of novel inhibitors and activators have further confirmed the important role of acetylation. In this review, we provide insights into the physiological process of acetylation and summarise its specific mechanisms and potential therapeutic effects on renal pathology.

Photoinduced Copper-Catalyzed 1,2-Difunctionalization of 1,3-Dienes with Aryl Diselenides.

Described herein is a photoinduced copper-catalyzed 1,2-difunctionalization of 1,3-dienes. The selenium atom radical was generated by the visible light irradiation of diselenides, triggering radical addition with 1,3-dienes to form allyl radical intermediate. Subsequent rapid Z/E isomerization allowed for thermodynamically favorable intermediate formation and enabled copper catalyzed stereoselective functionalization with various nucleophiles.

The mechanism by which enoxaparin sodium-high-viscosity bone cement reduces thrombosis by regulating CD40 expression in endothelial cells.

OBJECTIVE: PMMA bone cement leads to the development of local thrombi. Our study found that ES-PMMA bone cement, a novel material, can reduce local thrombosis. We used a simple and reproducible animal model to confirm the reduction in local thrombosis and preliminarily explored the associated molecular mechanism. METHODS: New Zealand rabbits, which were used to model thrombosis using extracorporeal carotid artery shunts, were divided into the following three groups, with 10 rabbits in each group: the sham group, PMMA group and ES-PMMA group. Four hours after modelling, experimental samples were collected, and the degree of thrombosis was compared between the groups. The expression of thrombomodulin in endothelial cells was quantified in vascular tissues samples. RESULTS: Thrombosis was observed in the PMMA group and ES-PMMA group but not in the sham group. The thrombosis weight was 0.00732 ± 0.00089 g/cm in the PMMA group and 0.00554 ± 0.00077 g/cm in the ES-PMMA group (P < 0.001). Quantitative real-time polymerase chain reaction (RT-qPCR) and Western blotting revealed that the expression of CD40, which can regulate thrombosis in vascular endothelial cells, was significantly lower in the ES-PMMA group than in the PMMA group. CONCLUSION: Compared with PMMA bone cement, ES-PMMA bone cement can reduce local thrombosis by decreasing the expression of the thrombus-associated regulatory protein CD40 in vascular endothelial cells.

Design of a Low-Cost Small-Size Fluxgate Sensor.

Traditional fluxgate sensors used in geomagnetic field observations are large, costly, power-consuming and often limited in their use. Although the size of the micro-fluxgate sensors has been significantly reduced, their performance, including indicators such as accuracy and signal-to-noise, does not meet observational requirements. To address these problems, a new race-track type probe is designed based on a magnetic core made of a Co-based amorphous ribbon. The size of this single-component probe is only Φ10 mm × 30 mm. The signal processing circuit is also optimized. The whole size of the sensor integrated with probes and data acquisition module is Φ70 mm × 100 mm. Compared with traditional fluxgate and micro-fluxgate sensors, the designed sensor is compact and provides excellent performance equal to traditional fluxgate sensors with good linearity and RMS noise of less than 0.1 nT. From operational tests, the results are in good agreement with those from a standard fluxgate magnetometer. Being more suitable for modern dense deployment of geomagnetic observations, this small-size fluxgate sensor offers promising research applications at lower costs.

Improved Resolution and Cost Performance of Low-Cost MEMS Seismic Sensor through Parallel Acquisition.

In earthquake monitoring, an important aspect of the operational effect of earthquake intensity rapid reporting and earthquake early warning networks depends on the density and performance of the deployed seismic sensors. To improve the resolution of seismic sensors as much as possible while keeping costs low, in this article the use of multiple low-cost and low-resolution digital MEMS accelerometers is proposed to increase the resolution through the correlation average method. In addition, a cost-effective MEMS seismic sensor is developed. With ARM and Linux embedded computer technology, this instrument can cyclically store the continuous collected data on a built-in large-capacity SD card for approximately 12 months. With its real-time seismic data processing algorithm, this instrument is able to automatically identify seismic events and calculate ground motion parameters. Moreover, the instrument is easy to install in a variety of ground or building conditions. The results show that the RMS noise of the instrument is reduced from 0.096 cm/s2 with a single MEMS accelerometer to 0.034 cm/s2 in a bandwidth of 0.1-20 Hz by using the correlation average method of eight low-cost MEMS accelerometers. The dynamic range reaches more than 90 dB, the amplitude-frequency response of its input and output within -3 dB is DC -80 Hz, and the linearity is better than 0.47%. In the records from our instrument, earthquakes with magnitudes between M2.2 and M5.1 and distances from the epicenter shorter than 200 km have a relatively high SNR, and are more visible than they were prior to the joint averaging.

Two Distinct Mechanisms of Inhibition of LpxA Acyltransferase Essential for Lipopolysaccharide Biosynthesis.

The lipopolysaccharide biosynthesis pathway is considered an attractive drug target against the rising threat of multi-drug-resistant Gram-negative bacteria. Here, we report two novel small-molecule inhibitors (compounds 1 and 2) of the acyltransferase LpxA, the first enzyme in the lipopolysaccharide biosynthesis pathway. We show genetically that the antibacterial activities of the compounds against efflux-deficient Escherichia coli are mediated by LpxA inhibition. Consistently, the compounds inhibited the LpxA enzymatic reaction in vitro. Intriguingly, using biochemical, biophysical, and structural characterization, we reveal two distinct mechanisms of LpxA inhibition; compound 1 is a substrate-competitive inhibitor targeting apo LpxA, and compound 2 is an uncompetitive inhibitor targeting the LpxA/product complex. Compound 2 exhibited more favorable biological and physicochemical properties than compound 1 and was optimized using structural information to achieve improved antibacterial activity against wild-type E. coli. These results show that LpxA is a promising antibacterial target and imply the advantages of targeting enzyme/product complexes in drug discovery.

miR-485 suppresses inflammation and proliferation of mesangial cells in an in vitro model of diabetic nephropathy by targeting NOX5.

Diabetic nephropathy (DN) is among the common complications of diabetes and is a major cause of end-stage kidney disease. Emerging data indicate that renal inflammation is involved in DN progression and aggravation. Still, the exact cellular mechanisms remain unclear. Dysregulated expression of microRNAs (miRNAs) is associated with multiple diseases, including DN. The relationship between miRNAs and inflammation in DN is also unexplored. Here, we evaluated the role of miR-485 in mediating the response of human mesangial cells (HMCs) to a high glucose (HG) concentration, and the potential underlying mechanism. We found that miR-485 expression is significantly decreased in HG-stimulated HMCs. Overexpression of miR-485 suppressed HG-induced proliferation of HMCs. Lower production of proinflammatory cytokines (i.e., TNF-α, IL-1ß, and IL-6) was observed in miR-485-overexpressing HMCs. Overexpression of miR-485 markedly suppressed the overexpression of extracellular-matrix proteins, e.g., collagen IV (Col IV) and fibronectin (FN), in HG-stimulated HMCs. Furthermore, miR-485 suppressed the expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 5 (NOX5), restrained the HG-induced HMC proliferation, downregulated the expression of proinflammatory cytokines, and inhibited the production of extracellular-matrix proteins in HMCs. These results provide new insights into the involvement of the miR-485-NOX5 signaling pathway in DN progression.

Neckio: Motivating Neck Exercises in Computer Workers.

Neck pain is common among computer workers who may spend too much time in a static posture facing their display. Regular breaks and variety in one's posture can help to prevent discomfort and pain. In order to understand how to support computer workers to do so regularly, we surveyed a convenience sample of computer workers (N = 130) regarding their work habits and their attitudes towards neck exercises at the workplace. The survey showed that they are highly motivated, but not able to comply with a neck exercise program. To address this challenge, we designed Neckio, a system that is aimed at encouraging posture variation and facilitating neck exercises at work. Neckio consists in an interactive application and a wireless angulation sensing appliance that can be mounted on the headset that office workers often use for reasons of privacy. Next to providing an interactive exercise program suitable for the workplace, its design places emphasis on an engaging user experience. We report a short-term user experience valuation of Neckio in an actual office environment (N = 10). Participants rated the overall user experience positively and reported to be intrinsically motivated to do the neck exercises. These results indicate the potential of the Neckio as a behavior change support technology to reduce the risk of developing neck pain in computer workers.

Defects in Efflux (oprM), ß-Lactamase (ampC), and Lipopolysaccharide Transport (lptE) Genes Mediate Antibiotic Hypersusceptibility of Pseudomonas aeruginosa Strain Z61.

Antibiotic hypersensitive bacterial mutants (e.g., Escherichia coliimp) are used to investigate intrinsic resistance and are exploited in antibacterial discovery to track weak antibacterial activity of novel inhibitor compounds. Pseudomonas aeruginosa Z61 is one such drug-hypersusceptible strain generated by chemical mutagenesis, although the genetic basis for hypersusceptibility is not fully understood. Genome sequencing of Z61 revealed nonsynonymous single-nucleotide polymorphisms in 153 genes relative to its parent strain, and three candidate mutations (in oprM, ampC, and lptE) predicted to mediate hypersusceptibility were characterized. The contribution of these mutations was confirmed by genomic restoration of the wild-type sequences, individually or in combination, in the Z61 background. Introduction of the lptE mutation or genetic inactivation of oprM and ampC genes alone or together in the parent strain recapitulated drug sensitivities. This showed that disruption of oprM (which encodes a major outer membrane efflux pump channel) increased susceptibility to pump substrate antibiotics, that inactivation of the inducible ß-lactamase gene ampC contributed to ß-lactam susceptibility, and that mutation of the lipopolysaccharide transporter gene lptE strongly altered the outer membrane permeability barrier, causing susceptibility to large antibiotics such as rifampin and also to ß-lactams.

Mode of Action of the Monobactam LYS228 and Mechanisms Decreasing In Vitro Susceptibility in Escherichia coli and Klebsiella pneumoniae.

The monobactam scaffold is attractive for the development of new agents to treat infections caused by drug-resistant Gram-negative bacteria because it is stable to metallo-ß-lactamases (MBLs). However, the clinically used monobactam aztreonam lacks stability to serine ß-lactamases (SBLs) that are often coexpressed with MBLs. LYS228 is stable to MBLs and most SBLs. LYS228 bound purified Escherichia coli penicillin binding protein 3 (PBP3) similarly to aztreonam (derived acylation rate/equilibrium dissociation constant [k2/Kd ] of 367,504 s-1 M-1 and 409,229 s-1 M-1, respectively) according to stopped-flow fluorimetry. A gel-based assay showed that LYS228 bound mainly to E. coli PBP3, with weaker binding to PBP1a and PBP1b. Exposing E. coli cells to LYS228 caused filamentation consistent with impaired cell division. No single-step mutants were selected from 12 Enterobacteriaceae strains expressing different classes of ß-lactamases at 8× the MIC of LYS228 (frequency, <2.5 × 10-9). At 4× the MIC, mutants were selected from 2 of 12 strains at frequencies of 1.8 × 10-7 and 4.2 × 10-9 LYS228 MICs were ≤2 µg/ml against all mutants. These frequencies compared favorably to those for meropenem and tigecycline. Mutations decreasing LYS228 susceptibility occurred in ramR and cpxA (Klebsiella pneumoniae) and baeS (E. coli and K. pneumoniae). Susceptibility of E. coli ATCC 25922 to LYS228 decreased 256-fold (MIC, 0.125 to 32 µg/ml) after 20 serial passages. Mutants accumulated mutations in ftsI (encoding the target, PBP3), baeR, acrD, envZ, sucB, and rfaI These results support the continued development of LYS228, which is currently undergoing phase II clinical trials for complicated intraabdominal infection and complicated urinary tract infection (registered at ClinicalTrials.gov under identifiers NCT03377426 and NCT03354754).

MiR-455-3p suppresses renal fibrosis through repression of ROCK2 expression in diabetic nephropathy.

Emerging evidence has shown that microRNAs (miRNAs) play a mediatory role in the pathogenesis of diabetic nephropathy (DN), but the function of the involved miRNAs is still incomplete. Here, we found that miR-455-3p was down-regulated in the human mesangial cells (HMC) and human proximal tubule epithelial cells (HK-2) stimulated with high glucose (HG) or transforming growth factor beta 1 (TGF-ß1). Rho-associated coiled coil-containing protein kinase 2 (ROCK2) was identified as a directed target of miR-455-3p. Overexpression of ROCK2 significantly attenuated the inhibitory effects of miR-455-3p on cell proliferation, extracellular matrix (ECM) synthesis and epithelial-mesenchymal transition (EMT) in HG-treated cells. Furthermore, the DN model was prepared by using high-fat feeding combined with Streptozotocin (STZ) induced rats, and the DN group was treated by injecting miR-455-3p agomir. The results of periodic acid-Schiff (PAS) and Masson staining showed that miR-455-3p overexpression improved the pathological changes of glomerular hypertrophy, mesangial amplification, and renal fibrosis. Additionally, miR-455-3p overexpression decreased ROCK2, proliferating cell nuclear antigen (PCNA) and Collagen I levels, and also reduced inflammatory cytokines TNF-α, MCP-1 and IL-1ß levels in vivo. Altogether, these results suggest that miR-455-3p plays an essential role in the treatment of renal fibrosis through repressing ROCK2 expression; and miR-455-3p might be an effective therapy for DN.

Optimization of novel monobactams with activity against carbapenem-resistant Enterobacteriaceae - Identification of LYS228.

Metallo-ß-lactamases (MBLs), such as New Delhi metallo-ß-lactamase (NDM-1) have spread world-wide and present a serious threat. Expression of MBLs confers resistance in Gram-negative bacteria to all classes of ß-lactam antibiotics, with the exception of monobactams, which are intrinsically stable to MBLs. However, existing first generation monobactam drugs like aztreonam have limited clinical utility against MBL-expressing strains because they are impacted by serine ß-lactamases (SBLs), which are often co-expressed in clinical isolates. Here, we optimized novel monobactams for stability against SBLs, which led to the identification of LYS228 (compound 31). LYS228 is potent in the presence of all classes of ß-lactamases and shows potent activity against carbapenem-resistant isolates of Enterobacteriaceae (CRE).

Qualitative analysis of Psoraleae Fructus by HPLC-DAD/TOF-MS fingerprint and quantitative analysis of multiple components by single marker.

A variety of bioactive substances may account for the recognized efficacy and wide clinical application of Psoraleae Fructus in China. A high-performance liquid chromatography-diode array detector (HPLC-DAD) fingerprint method was developed to present the comprehensive phytochemical profile of the crude drug. Thirteen major compounds were separated and identified by HPLC coupled with time-of-flight mass spectrometry (HPLC/TOF-MS), namely psoralenoside (PO), isopsoralenoside (IPO), psoralen (PS), isopsoralen (IPS), neobavaisoflavone (NBF), bavachin (BC), corylin (CN), bavachromene (BCM), psoralidin (PD), isobavachalcone (IBC), bacachinin (BCN), corylifol A (CA) and bakuchiol (BK). Then quantitative analysis of multiple components by single marker (QAMS) was applied in content determination of PO, IPO, PS, IPS, BC, IBC, BCN, CA and BK, with NBF as the internal standard. The calculation results indicated no significant difference from the traditional external standard method (p > 0.05, RSD < 2.62%), suggesting that QAMS is a reliable and convenient method for content determination of multiple chemical compositions, especially when there is a shortage of reference substances. In conclusion, simultaneous qualitative and quantitative analysis of Psoraleae Fructus may be fulfilled through the newly proposed method of QAMS combined with HPLC-DAD/TOF-MS fingerprint.

Determinants of Antibacterial Spectrum and Resistance Potential of the Elongation Factor G Inhibitor Argyrin B in Key Gram-Negative Pathogens.

Argyrins are natural products with antibacterial activity against Gram-negative pathogens, such as Pseudomonas aeruginosa, Burkholderia multivorans, and Stenotrophomonas maltophilia We previously showed that argyrin B targets elongation factor G (FusA). Here, we show that argyrin B activity against P. aeruginosa PAO1 (MIC = 8 µg/ml) was not affected by deletion of the MexAB-OprM, MexXY-OprM, MexCD-OprJ, or MexEF-OprN efflux pump. However, argyrin B induced expression of MexXY, causing slight but reproducible antagonism with the MexXY substrate antibiotic ciprofloxacin. Argyrin B activity against Escherichia coli increased in a strain with nine tolC efflux pump partner genes deleted. Complementation experiments showed that argyrin was effluxed by AcrAB, AcrEF, and MdtFX. Argyrin B was inactive against Acinetobacter baumannii Differences between A. baumannii and P. aeruginosa FusA proteins at key residues for argyrin B interaction implied that natural target sequence variation impacted antibacterial activity. Consistent with this, expression of the sensitive P. aeruginosa FusA1 protein in A. baumannii conferred argyrin susceptibility, whereas resistant variants did not. Argyrin B was active against S. maltophilia (MIC = 4 µg/ml). Spontaneous resistance occurred at high frequency in the bacterium (circa 10-7), mediated by mutational inactivation of fusA1 rather than by amino acid substitutions in the target binding region. This strongly suggested that resistance occurred at high frequency through loss of the sensitive FusA1, leaving an alternate argyrin-insensitive elongation factor. Supporting this, an additional fusA-like gene (fusA2) is present in S. maltophilia that was strongly upregulated in response to mutational loss of fusA1.

Urinary RBP and NGAL Levels are Associated with Nephropathy in Patients with Type 2 Diabetes.

BACKGROUND/AIMS: The diagnosis of type 2 diabetic nephropathy (T2DN) patients is important to prevent the long-term damaging effects of kidney loss in patients with diabetes and is decisive for patient outcomes. The aim of this study was to explore urine retinol binding protein (RBP) and neutrophil gelatinase-associated lipocalin (NGAL) in T2DN patients with and without albuminuria. METHODS: A total of 293 T2DN patients were divided into three groups according to their urine albumin/urine creatinine ratio (UACR): normoalbuminuria group (UACR<30 mg/g, n=100), microalbuminuria group (UACR 30-300 mg/g, n=100) and macroalbuminuria group (UACR>300 mg/g, n=93); 50 non-diabetic subjects were recruited as the control group. The levels of urine RBP, NGAL, TNF-α and IL-18 in T2DN patients and non-diabetic subjects were measured using ELISA assays. RESULTS: We first analyzed the clinical characteristics of the control and T2DN groups and found that urine NGAL, RBP, TNF-α and IL-18 levels were significantly increased and significantly correlated with the degree of albuminuria. In addition, univariate linear regression analysis showed that urine RBP was associated with UACR, BMI, Scr, BUN, TG, disease duration, SBP, NGAL, TNF-α and IL-18 levels, and urine NGAL was positively correlated with UACR, Scr, BUN, RBP, TNF-α and IL-18 levels. CONCLUSION: The results indicate that urine levels of NGAL and RBP may be independently associated with albuminuria in T2DN and may serve as novel biomarkers for the identification of T2DN.

Correlation between the High Density Lipoprotein and its Subtypes in Coronary Heart Disease.

BACKGROUND/AIMS: To detect the changes of high density lipoprotein (HDL) and its subtypes in serum of patients with coronary heart disease (CHD). METHODS: 337 hospitalized patients were selected from our hospital during August, 2014 - January, 2015, and divided into CHD group (n = 190) and control group (n = 127). Lipoprint lipoprotein analyzer was used to classify low density lipoprotein (LDL) particle size and its sub-components, as well as HDL particle size and its sub-components. The changes of the subtypes in patients with CHD were statistically analyzed. The possible mechanism was explored. RESULTS: (1) Compared with the control group, the concentration of HDL in CHD patients reduced, HDLL significantly decreased (P < 0.001), while HDLS increased (P < 0.001); (2) In the patients with HDL less than 1.04 mmol/L among CHD, all HDL subtypes reduced, but HDLL had the most significant decreased; (3) HDL and all HDL subtypes were positively correlated with apolipoprotein A-I (apoA-I), of which, HDLL had the biggest correlation with apoA-I (P < 0.001); (4) HDL subtypes had good correlation with HDL, of which, HDLM had a maximum correlation with HDL (P < 0.001). CONCLUSION: HDL maturation disorders existed in the serum of CHD patients, HDLL may be protected factor for CHD, whose decrease was closely related wit the risk increase of CHD. The cardiovascular protection function of HDLL may be related with apoA-I content.

Association between glutathione S-transferase T1 null genotype and risk of lung cancer: a meta-analysis of 55 studies.

The relationship between glutathione S-transferase T1 (GSTT1) gene polymorphism and the risk of lung cancer from the published reports are still conflicting. This study was conducted to evaluate the relationship between GSTT1 polymorphism and the risk of lung cancer. A comprehensive research was conducted through the databases, and 55 studies were recruited into this meta-analysis for the association of null genotype of GSTT1 with lung cancer susceptibility, consisting of 15,140 patients with lung cancer and 16,662 controls. There was a significant association between GSTT1 null genotype and lung cancer risk in the overall populations (OR = 1.138, 95% CI = 1.032-1.255, P heterogeneity = 0.000, P = 0.009). Furthermore, GSTT1 null genotype was associated with the lung cancer risk in Asians (OR = 1.469, 95% CI = 1.228-1.757, P heterogeneity = 0.000, P = 0.000). However, GSTT1 null genotype was not associated with the risk of lung cancer in Caucasians and Africans. In conclusion, GSTT1 null genotype is associated with the lung cancer in overall populations and in Asians.