Efficient Acidic Photoelectrochemical Water Splitting Enabled by Ru Single Atoms Anchored on Hematite Photoanodes.

Photoelectrochemical (PEC) water splitting in acidic media holds promise as an efficient approach to renewable hydrogen production. However, the development of highly active and stable photoanodes under acidic conditions remains a significant challenge. Herein, we demonstrate the remarkable water oxidation performance of Ru single atom decorated hematite (Fe2O3) photoanodes, resulting in a high photocurrent of 1.42 mA cm-2 at 1.23 VRHE under acidic conditions. Comprehensive experimental and theoretical investigations shed light on the mechanisms underlying the superior activity of the Ru-decorated photoanode. The presence of single Ru atoms enhances the separation and transfer of photogenerated carriers, facilitating efficient water oxidation kinetics on the Fe2O3 surface. This is achieved by creating additional energy levels within the Fe2O3 bandgap and optimizing the free adsorption energy of intermediates. These modifications effectively lower the energy barrier of the rate-determining step for water splitting, thereby promoting efficient PEC hydrogen production.

Enantioselective Cyanofunctionalization of Aromatic Alkenes via Radical Anions.

Alkene radical ions constitute an integral and unique class of reactive intermediates for the synthesis of valuable compounds because they have both unpaired spins and charge. However, relatively few synthetic applications of alkene radical anions have emerged due to a dearth of generally applicable and mild radical anion generation approaches. Precise control over the chemo- and stereoselectivity in alkene radical anion-mediated processes represents another long-standing challenge due to their high reactivity. To overcome these issues, here, we develop a new redox-neutral strategy that seamlessly merges photoredox and copper catalysis to enable the controlled generation of alkene radical anions and their orthogonal enantioselective cyanofunctionalization via distonic-like species. This new strategy enables highly regio-, chemo-, and enantioselective hydrocyanation, deuterocyanation, and cyanocarboxylation of alkenes without stoichiometric reductants or oxidants under visible light irradiation. This protocol provides a new blueprint for the exploration of the transformation potential of alkene radical anions.

Ir Single Atoms Boost Metal-Oxygen Covalency on Selenide-Derived NiOOH for Direct Intramolecular Oxygen Coupling.

This investigation probes the intricate interplay of catalyst dynamics and reaction pathways during the oxygen evolution reaction (OER), highlighting the significance of atomic-level and local ligand structure insights in crafting highly active electrocatalysts. Leveraging a tailored ion exchange reaction followed by electrochemical dynamic reconstruction, we engineered a novel catalytic structure featuring single Ir atoms anchored to NiOOH (Ir1@NiOOH). This novel approach involved the strategic replacement of Fe with Ir, facilitating the transition of selenide precatalysts into active (oxy)hydroxides. This elemental substitution promoted an upward shift in the O 2p band and intensified the metal-oxygen covalency, thereby altering the OER mechanism toward enhanced activity. The shift from a single-metal site mechanism (SMSM) in NiOOH to a dual-metal-site mechanism (DMSM) in Ir1@NiOOH was substantiated by in situ differential electrochemical mass spectrometry (DEMS) and supported by theoretical insights. Remarkably, the Ir1@NiOOH electrode exhibited exceptional electrocatalytic performance, achieving overpotentials as low as 142 and 308 mV at current densities of 10 and 1000 mA cm-2, respectively, setting a new benchmark for the electrocatalysis of OER.

Advancing BiVO4 Photoanode Activity for Ethylene Glycol Oxidation via Strategic pH Control.

The photoelectrochemical (PEC) conversion of organic small molecules offers a dual benefit of synthesizing value-added chemicals and concurrently producing hydrogen (H2). Ethylene glycol, with its dual hydroxyl groups, stands out as a versatile organic substrate capable of yielding various C1 and C2 chemicals. In this study, we demonstrate that pH modulation markedly enhances the photocurrent of BiVO4 photoanodes, thus facilitating the efficient oxidation of ethylene glycol while simultaneously generating H2. Our findings reveal that in a pH = 1 ethylene glycol solution, the photocurrent density at 1.23 V vs. RHE can attain an impressive 7.1 mA cm-2, significantly surpassing the outputs in neutral and highly alkaline environments. The increase in photocurrent is attributed to the augmented adsorption of ethylene glycol on BiVO4 under acidic conditions, which in turn elevates the activity of the oxidation reaction, culminating in the maximal production of formic acid. This investigation sheds light on the pivotal role of electrolyte pH in the PEC oxidation process and underscores the potential of the PEC strategy for biomass valorization into value-added products alongside H2 fuel generation.

The prognosis biomarkers based on m6A-related lncRNAs for myeloid leukemia patients.

BACKGROUND: Chronic myeloid leukemia (CML) and acute myeloid leukemia (AML) are two common malignant disorders in leukemia. Although potent drugs are emerging, CML and AML may still relapse after the drug treatment is stopped. N6-methyladenosine (m6A) and lncRNAs play certain roles in the occurrence and development of tumors, but m6A-modified LncRNAs in ML remain to be further investigated. METHODS: In this study, we extracted and analyzed the TCGA gene expression profile of 151 ML patients and the clinical data. On this basis, we then evaluated the immune infiltration capacity of ML and LASSO-penalized Cox analysis was applied to construct the prognostic model based on m6A related lncRNAs to verify the prognostic risk in clinical features of ML. Quantitative reverse transcription PCR was used to detect the expression level of LncRNA in in ML cell lines K562, MOLM13 and acute monocytic leukemia cell line THP-1. RESULTS: We found 70 m6A-related lncRNAs that were related to prognosis, and speculated that the content of stromal cells and immune cells would correlate with the survival of patients with ML. Next, Prognostic risk model of m6A-related lncRNAs was validated to have excellent consistency in clinical features of ML. Finally, we verified the expression levels of CRNDE, CHROMR and NARF-IT1 in ML cell lines K562, MOLM13 and acute monocytic leukemia cell line THP-1, which were significant. CONCLUSIONS: The research provides clues for the prognosis prediction of ML patients by using the m6A-related lncRNAs model we have created, and clarifies the accuracy and authenticity of it.

Comparison of acquisition rate and agreement of axial length with two swept-source optical coherence tomographers and a partial coherence interferometer.

PURPOSE: To assess the acquisition rate and agreement of axial length (AL) measurements with the OA-2000, Anterion, and IOLMaster 500 in cataractous patients. METHODS: In total, 298 eyes of 191 cataractous patients were enrolled and scanned with the three devices in random order. The success rate of AL measurements per device was calculated and a chi-square test was utilized to identify the differences in acquisition rate between the three devices. Logistic regression analysis was applied to evaluate the association of different cataract types and severity with the AL measurement acquisition rate. Bland-Altman plots were mapped to appraise the agreement of AL values. RESULTS: AL measurements were successfully achieved in 288 eyes (96.64%) with the OA-2000, in 282 eyes (94.30%) with the Anteiron, and in 246 eyes (82.55%) with the IOLMaster 500. Significant differences in the acquisition rate were found between either of the SS-OCT devices and IOLMaster 500 by chi-square analysis (P < 0.001). No significant difference was noted between OA-2000 and Anterion. Increasing severity of posterior subcapsular cataract was associated with a higher failure rate with the IOLMaster 500. Bland-Altman analysis identified good agreement between the three biometers with narrow 95% limits of agreement. CONCLUSIONS: The OA-2000 and Anterion showed similarly higher acquisition rate of AL measurements than IOLMaster 500 in cataractous patients. Good agreement for AL values was found between the three biometers in cataractous patients.

Repeatability of a new swept-source optical coherence tomographer and agreement with other three optical biometers.

PURPOSE: To investigate the repeatability of Anterion and compare the agreement of ocular biometric measurements and predicted intraocular lens (IOL) powers with other three optical biometers. METHODS: Flat keratometry (Kf), steep keratometry (Ks), J0 and 45 vectors, central cornea thickness (CCT), anterior chamber depth (ACD), and axial length (AL) from the Anterion, IOLMaster 700, Lenstar LS 900, and OA-2000 were recorded. The IOL powers were calculated with the Hoffer Q, Holladay 1, SRK/T, and Haigis formulas. The repeatability was evaluated using the within-subject standard deviation (Sw), repeatability coefficient (RC), coefficient of variation (COV), and intraclass correlation coefficient (ICC). Inter-device agreement between the four biometers was assessed with the 95% limits of agreement. RESULTS: In total, 101 right eyes of 101 participants were enrolled. The Anterion showed good repeatability for all the included biometric parameters with all the CoV ≤ 0.30% and ICC ≥ 0.930 except for J45 with moderate repeatability (ICC was 0.849). Good agreement was found among the four devices for Kf, Ks, J0, J45, ACD, and AL. Generally, wide 95% LoA was found for the predicted IOL powers with the four IOL calculation formulas between the four devices. CONCLUSIONS: The Anterion showed good repeatability of biometric measurements for most parameters. Good agreement among the four optical biometers was achieved for all the parameters except for CCT and the predicted IOL power. The AL values exhibited the best repeatability with Anterion and the best agreement among the biometers in our study.

Control of pathogenic fungi on Panax notoginseng by volatile oils from the food ingredients Allium sativum and Foeniculum vulgare.

To screen natural drugs with strong inhibitory effects against pathogenic fungi related to P. notoginseng, the antifungal activities of garlic and fennel EOs were studied by targeting P. notoginseng disease-associated fungi, and the possible action mechanisms of garlic and fennel EOs as plant fungicides were preliminarily discussed. At present, the antifungal mechanism of EOs has not been fully established. Therefore, understanding the antifungal mechanism of plant EOs is helpful to address P. notoginseng diseases continuous cropping disease-related obstacles and other agricultural cultivation problems. First, the Oxford cup method and chessboard were used to confirm that the EOs and oxamyl had a significant inhibitory effect on the growth of Fusarium oxysporum. F. oxysporum is the main pathogen causing root rot of P. notoginseng and the preliminary study on the antifungal mechanisms of the EOs against F. oxysporum showed that the inhibition of EOs mainly affects cell membrane permeability and cell processes and affects the enzyme activities of micro-organism, to achieve antifungal effects. Finally, an in vivo model verified that both two EOs could significantly inhibit the occurrence of root rot caused by F. oxysporum.

Design and Preparation of NiFe2O4@FeOOH Composite Electrocatalyst for Highly Efficient and Stable Oxygen Evolution Reaction.

Rational design and constructing earth-abundant electrocatalysts for efficient electrocatalytic water splitting is a crucial challenge. Herein, we report a simple and efficient one-step electrochemical synthetic route of the NiFe2O4@FeOOH composite electrocatalyst for the oxygen evolution reaction. The unique morphology of the NiFe2O4 nanoflowers loaded on FeOOH nanosheets allows more active sites to be exposed and promote charge transfer as well as gas release, and the resulting electrode enables a current density of 10 mA cm-2 at a low overpotential of 255 mV with outstanding stability at a current density of 100 mA cm-2 for 300 h.

Two-Terminal Perovskite-Based Tandem Solar Cells for Energy Conversion and Storage.

The organic-inorganic hybrid perovskite solar cells present a rapid improvement on power conversion efficiency from 3.8% to 25.5% in the past decades. Owing to the tuneable bandgaps, low-cost, and ease of fabrication, perovskites become ideal candidate materials for fabricating tandem solar cells, especially for efficient and high-voltage monolithic two-terminal devices. In this review, an overview of recent advances in various monolithic perovskite-based tandem solar cells with a focus on the key challenges is provided. Subsequently, the recombination layer materials, construction of wide-bandgap perovskite layer, stability of narrow-bandgap, and current matching principle in tandems are highlighted in order to optimize the output voltage and conversion efficiency of tandem solar cells. Finally, the recent progress is summarized with a focus on potential applications of tandem solar cells for energy conversion and storage, including hydrogen production by water splitting, CO2 reduction, supercapacitors, and rechargeable batteries, benefiting from the adjustable output voltage of tandem solar cells. It is hoped that this work can offer a feasible strategy to explore more possibilities for fabricating new two-terminal tandem solar cells with high voltage and high conversion efficiency for energy conversion and storage.

Homoharringtonine inhibits the progression of hepatocellular carcinoma by suppressing the PI3K/AKT/GSK3ß/Slug signaling pathway.

Homoharringtonine (HHT), was first isolated from the bark of Cephalotaxus harringtonia (Knight ex J. Forbes) K. Koch and Cephalotaxus fortunei Hook trees. The bark extract is used to treat leukemia and in recent years has also been used in traditional Chinese medicine (TCM) to treat solid tumors. However, the inhibitory mechanism of HHT in the progression of hepatocellular carcinoma (HCC) is rarely studied. We aimed to evaluate the antitumor efficacy of HHT on HCC in vitro and in vivo and elucidate the underlying molecular mechanism(s). HCC cell lines, including HCCLM3, HepG2, and Huh7, were used to evaluate the antitumor efficacy of HHT in vitro. Cytotoxicity and proliferative ability were evaluated by MTT and colony formation assays. Cell cycle progression and apoptosis in HHT-treated HCC cells were evaluated by flow cytometry. To determine the migration and invasion abilities of HCC cells, wound-healing and Transwell assays were used. Finally, western blot analysis was used to reveal the proteins involved. We also established a xenograft nude mouse model for in vivo assessments of the preclinical efficacy of HHT, mainly using hematoxylin and eosin staining, immunohistochemistry, ultrasound imaging (USI), and magnetic resonance imaging (MRI). HHT suppressed the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of HCC cells, and induced cell cycle arrest at the G2 phase and apoptosis. In the HCC xenograft model, HHT showed an obvious tumor-suppressive effect. Surprisingly, Slug expression was also decreased by HHT via the PI3K/AKT/GSK3ß signaling pathway at least partially suppressed the growth of HCC via the PI3K/AKT/GSK3ß/Slug signaling pathway.

Demography of Mythimna separata (Lepidoptera: Noctuidae) at outdoor fluctuating temperatures.

The oriental armyworm Mythimna separata (Walker) (Lepidoptera: Noctuidae) is a major migratory pest of cereal crops in East Asia, South Asia and Australia. To comprehensively understand the ecological tolerance of M. separata, we collected life table data of individuals from four consecutive generations reared under outdoor natural fluctuating temperatures from 15 April to 17 October 2018 in Yangling, Shaanxi, China. The results showed that the immature stage in early summer and summer were shorter than in spring and autumn. High mortality in late larval instar and pupal stages was observed in the summer generation. The adult pre-oviposition period in autumn was longer than the other seasons. The population in the earlier two seasons had heavier pupae and higher fecundity than the population in the latter two seasons. The intrinsic rate of increase and the finite rate of increase was the highest in early summer (r = 0.1292 day-1, λ = 1.1391 day-1), followed by spring (r = 0.1102 day-1, λ = 1.1165 day-1), and was the lowest in summer (r = 0.0281 day-1, λ = 1.0293 day-1). The results of this study would be useful to predict the population dynamics of M. separata and deepen our standing of the adaptiveness of this migratory pest in natural fluctuating ambient environments.

Chemical Constituents of the Essential oil from Cuminum cyminum L. and Its Antifungal Activity against Panax notoginseng Pathogens.

Cuminum cyminum L. (Cumin) is a flavoring agent that is commonly used worldwide, and is rich in essential oil. Essential oils (Eos) have been intensively investigated in regard to their potential for disease control in plants, which is provided a chance for the blossom of green pesticides. The chemical components of Cumin essential oil (CEO) were revealed by GC/MS, such as cuminaldehyde (44.53 %), p-cymene (12.14 %), (-)-ß-pinene (10.47 %) and γ-terpinene (8.40 %), and found they can inhibit the growth of P. notoginseng-associated pathogenic fungi in vitro and the inhibitory effect of cuminaldehyde was similar to that of hymexazol. SEM and TEM images demonstrated that cuminaldehyde and CEO increased cell permeability and disrupted membrane integrity. The expression of disease-related genes of Fusarium oxysporum showed that CEO induced the expression of most genes, which disrupted biosynthesis, metabolism and signaling pathways. These studies verified the potential of CEO as a plant fungicide that is environmentally friendly and provided ideas for developing new products for controlling root diseases that affect P. notoginseng.

The effects of stereotactic body radiotherapy on peripheral natural killer and CD3+CD56+ NKT-like cells in patients with hepatocellular carcinoma.

BACKGROUND: Both natural killer (NK) and CD3+CD56+natural killer T (NKT)-like cells play critical roles in the antitumor response. This study aimed to explore the effects of stereotactic body radiotherapy (SBRT) on peripheral NK and NKT-like cells in patients with hepatocellular carcinoma (HCC), and to identify possible surface markers on these cells that correlate with the prognosis. METHODS: Twenty-five HCC patients were prospectively enrolled in our study, and 10 healthy individuals were served as healthy controls. Flow cytometry was used to determine the counts and the percentages of peripheral NK and NKT-like cells, cells with certain receptors, and cells with intracellular interferon-γ and TNF-α secretion at different time points, including time points of prior to SBRT, at post-SBRT, and 3-month and 6-month after treatment. The Kaplan-Meier method with the log-rank test was applied for survival analysis. RESULTS: The peripheral NKT-like cells was increased at post-SBRT. Meanwhile, elevated levels of inhibitory receptors and reduced levels of activating receptors of NK cells were also observed in NK cells at post-SBRT, but the levels was not significantly different at 3-month and 6-month as compared with the baseline levels. Lower percentage of NKp30+NK cells before SBRT and higher percentage of CD158b+NK cells after SBRT were associated with poor progression-free survival. In addition, higher percentage of CD3+CD56+ NKT-like cells was associated with a higher overall survival rate in HCC patients. CONCLUSIONS: SBRT has an apparent effect on both peripheral NK and CD3+CD56+NKT-like cells. Lower percentage of NKp30+NK cells before SBRT and higher percentage of CD158b+NK cells after SBRT are correlated with poor patients' PFS. Higher percentage of CD3+CD56+ NKT-like cells is associated with higher OS in HCC patients.

[Value of airway pH monitoring in determining the association between chronic cough and laryngopharyngeal reflux in children].

OBJECTIVE: To study the value of airway pH monitoring in determining the association between chronic cough and laryngopharyngeal reflux (LPR) in children. METHODS: A total of 274 children with chronic cough who were treated from January 2016 to December 2019 were enrolled. The DX-pH detection system was used to conduct 24-hour airway pH monitoring. The association between chronic cough and LPR was analyzed. RESULTS: Among the 274 children, there were 168 boys and 106 girls, with a median age of 62.8 months and a median airway pH value of 7.3. Of all the 274 children, 99 (36.1%) had LPR, and the incidence rate of LPR was 36.9% (62/168) in boys and 34.9% (37/106) in girls (P=0.737). The comparison of the incidence rate of LPR among children aged < 1 year, 1-6 years, and > 6 years showed that the younger children had a significantly higher incidence rate of LPR than the older ones (P=0.003). There was no significant difference in the incidence of LPR between the two groups with chronic cough of unknown etiology and definite etiology. The incidence of chronic cough was positively correlated with that of LPR (rs=0.861, P < 0.01). Among the 99 children with positive RYAN index, 65 (66%) suffered from simple LPR. CONCLUSIONS: LPR is highly associated with the development of chronic cough, and airway pH monitoring may be a safe and effective method for the diagnosis of LPR.

Synthesis and biological activity of new bisbenzofuran-imidazolium salts.

A series of novel bisbenzofuran-imidazolium salts were designed and prepared. The in vitro antitumor activity of these derivatives was evaluated against a panel of human tumor cell lines (A549, HL-60, MCF-7, SMMC-7721 and SW480). Results demonstrated that 2-methyl-benzimidazole ring and substitution of the imidazolyl-3-position with a 4-methoxyphenacyl or 2-naphthylacyl substituent were important for promoting cytotoxic activity. Notably, compound 23 was found to be the most potent compound with IC50 values of 0.64-1.47 µM against five human tumor cell lines, and exhibited higher selectivity to MCF-7 and SW-480 cell lines with IC50 values 15.3-fold and 9.1-fold lower than DDP.

Effectiveness and safety assessment of drospirenone/ethinyl estradiol tablet in treatment of PCOS patients: a single center, prospective, observational study.

BACKGROUND: To investigate the effectiveness and safety of 3 mg drospirenone and 20 µg ethinyl estradiol tablet (3 mg DRSP/20 µg EE) in the treatment of polycystic ovary syndrome (PCOS). METHODS: This single center, prospective observational study was conducted in 140 patients with PCOS. They were prescribed 3 mg DRSP/20 µg EE in a 24/4/ regimen for 3 months. Patients were instructed to take oral DRSP/EE tablets (once daily) on the 2nd day of menstruation, for 28 consecutive days for 1 cycle. After 3 months of treatment, anthropometric assessments along with variations in sex hormones related index, glucolipid metabolic index, changes in bilateral ovarian volume, as well as adverse effect of the combination were evaluated. RESULTS: When compared to baseline, body mass index (BMI, 22.07 ± 4.09 vs. 21.35 ± 3.22, p < 0.001) and waist hip ratio (WHR, 0.86 ± 0.07 vs. 0.854 ± 0.06, p = 0.026) decreased significantly after treatment. Sex-hormones such as luteinizing hormone (LH) (10.88 vs. 5.81 U/L), testosterone (T) (1.85 vs. 1.51 nmol/L) and free androgen index (FAI) (5.37 vs. 1.50) decreased significantly after treatment (p < 0.001). Follicular stimulating hormone (FSH) increased significantly at 3 months as compared to before treatment (5.13 vs. 5.42 U/L, p = 0.009). Plasma insulin (11.03 vs. 11.10 pmol/L), fasting (4.97 vs. 4.93 mmol/L) and 2 h-blood glucose levels (7.18 vs. 7.04 mmol/L) did not change when compared to baseline. Plasma triglycerides (TG, 1.32 vs. 1.65 mmol/L) significantly increased 3 months after treatment when compared to before treatment (p < 0.001). However, high density lipoprotein-cholesterol (HDL-C) levels increased significantly after treatment (1.41 vs. 1.57 mmol/L, p < 0.001). It was seen that, when compared to baseline, bilateral ovarian volume (left and right) was significantly lower after treatment (p < 0.05). It was seen that 81 patients reported no adverse reactions. Of the common discomforts reported, breast swelling and pain, gastrointestinal disorder and dizziness and headache were most frequent. CONCLUSIONS: Treatment of PCOS patients with3 mg DRSP/20 µg EE has shown beneficial hormonal and lipid profile along with considerable safety profile. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900022001, March 2019, retrospectively registered.

The association of plasma peroxiredoxin 3 with insulin in pregnant women.

Peroxiredoxin 3 (PRX3) is predominantly located in mitochondria and plays a major role in scavenging hydrogen peroxide of mitochondria. In the present study, we detected plasma PRX3 in pregnant women receiving oral glucose tolerance test at 24-28 gestational weeks. Plasma PRX3 was significantly increased about 1 h later than insulin secretion. In vitro detection of PRX3 in mouse islet cells showed up-regulation by more than 2-fold at 1 h and reached its top at 2 h of glucose stimulation, and the PRX3 level in cultured mediums was concomitantly elevated in a glucose concentration-dependent manner. In addition, both fasting plasma insulin and PRX3 were significantly higher in the subjects of term pregnancy as compared to that at 24-28 gestational weeks, and there was a positive correlation between plasma PRX3 and insulin. Our results indicate that PRX3 plays an active role in the response to insulin release. The positive association of plasma PRX3 and insulin suggest PRX3 to be a potential indicator of high insulin resistance.

Significant Decrease in Activation Temperature for the Generation of Strong Basicity: A Strategy of Endowing Supports with Reducibility.

Mesoporous solid strong bases are quite attractive due to their good catalytic performance for applications as environmentally friendly catalysts in various reactions. However, pretty harsh conditions are usually compulsory for the fabrication of strong basicity by using traditional thermal activation (e.g., 700 °C for the activation of base precursor KNO3 supported on mesoporous Al2O3). This is energy intensive and harmful to the mesoporous structure. In this study, we report a strategy of endowing supports with reducibility (ESWR) by doping low-valence Cr3+ into mesoporous Al2O3, so that the activation temperature for basicity generation is decreased significantly. Fascinatingly, KNO3 on mesoporous Al2O3 can be motivated to basic sites completely at the temperature of 400 °C via the ESWR strategy, which is much lower than the conventional thermal activation (700 °C). We have demonstrated that the redox reciprocity between KNO3 and Cr3+ is responsible for the low-temperature conversion, and Cr6+ is formed quantitatively as the oxidation product. The obtained solid bases possessing ordered mesostructure and strong basicity provide promising candidates for base-catalyzed synthesis of dimethyl carbonate via transesterification. The catalytic activity is obviously higher than a typical solid base like MgO as well as a series of reported basic catalysts containing alkali metal and alkaline-earth metal oxides.

Plasma level of peroxiredoxin 3 in patients with polycystic ovarian syndrome.

BACKGROUND: As a member of peroxiredoxin (PRX) family, PRX3 is predominantly located in mitochondria and plays an important role of free radical scavenging. Since a body of evidence demonstrated the involvement of PRX3 in insulin secretion, insulin sensitivity, and glucose metabolism, the present study was conducted to investigate the role of PRX3 in the pathogenesis of polycystic ovarian syndrome (PCOS) featured in insulin resistance. METHODS: Enzyme-linked immunosorbent assay was performed to detect plasma PRX3 in PCOS patients and control subjects. Levels of reactive oxygen species (ROS) and oxidized PRXs were detected in mouse islet cells treated with gradient glucose. RESULTS: We did not find significant difference of fasting plasma PRX3 between PCOS patients and controls. No association was noticed between fasting plasma PRX3 and fasting plasma glucose or insulin. After oral glucose tolerance test (OGTT), PCOS patients showed higher levels of both glucose and insulin as compared to controls. The plasma level of PRX3 was significantly increased at 2 h and began to fall back at 3 h of OGTT. There was a one-hour time lag of peak values between plasma PRX3 and insulin, and the plasma PRX3 at 2 h was positively correlated with the insulin level at 1 h of OGTT of PCOS patients. In addition, the level of ROS was significantly elevated at 1 h and oxidized PRX3 was increased dramatically at 2 h of 16.7mM glucose stimulation in mouse islet cells. CONCLUSION: It seems that PRX3 does not show its antioxidant function under baseline conditions. Instead, PRX3 responds to oxidative stress induced by rapid increase of insulin and glucose in patients with PCOS.