ROS-induced oxidative stress is a major contributor to sperm cryoinjury.

STUDY QUESTION: What is the mechanism behind cryoinjury in human sperm, particularly concerning the interplay between reactive oxygen species (ROS) and autophagy, and how does it subsequently affect sperm fate? SUMMARY ANSWER: The freeze-thaw operation induces oxidative stress by generating abundant ROS, which impairs sperm motility and activates autophagy, ultimately guiding the sperm toward programmed cell death such as apoptosis and necrosis, as well as triggering premature capacitation. WHAT IS KNOWN ALREADY: Both ROS-induced oxidative stress and autophagy are thought to exert an influence on the quality of frozen-thawed sperm. STUDY DESIGN, SIZE, DURATION: Overall, 84 semen specimens were collected from young healthy fertile males, with careful quality evaluation. The specimens were split into three groups to investigate the ROS-induced cryoinjury: normal control without any treatment, sperm treated with 0.5 mM hydrogen peroxide (H2O2) for 1 h, and sperm thawed following cryopreservation. Samples from 48 individuals underwent computer-assisted human sperm analysis (CASA) to evaluate sperm quality in response to the treatments. Semen samples from three donors were analyzed for changes in the sperm proteome after H2O2 treatment, and another set of samples from three donors were analyzed for changes following the freeze-thaw process. The other 30 samples were used for fluorescence-staining and western blotting. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sperm motility parameters, including progressive motility (PR %) and total motility (PR + NP %), were evaluated using the CASA system on a minimum of 200 spermatozoa. The proteomic profiles were determined with label-free mass spectrometry (MS/MS) and protein identification was performed via ion search against the NCBI human database. Subsequently, comprehensive bioinformatics was applied to detect significant proteomic changes and functional enrichment. Fluorescence-staining and western blot analyses were also conducted to confirm the proteomic changes on selected key proteins. The ROS level was measured using 2',7'-dichlorodihydrofluorescein diacetate labeling and the abundance of bioactive mitochondria was determined by evaluating the inner mitochondrial membrane potential (MMP) level. Molecular behaviors of sequestosome-1 (p62 or SQSTM1) and microtubule-associated proteins 1A/1B light chain 3 (LC3) were monitored to evaluate the state of apoptosis in human sperm. Fluorescent probes oxazole yellow (YO-PRO-1) and propidium iodide (PI) were utilized to monitor programmed cell death, namely apoptosis and necrosis. Additionally, gradient concentrations of antioxidant coenzyme Q10 (CoQ10) were introduced to suppress ROS impacts on sperm. MAIN RESULTS AND THE ROLE OF CHANCE: The CASA analysis revealed a significant decrease in sperm motility for both the H2O2-treatment and freeze-thaw groups. Fluorescence staining showed that high ROS levels were produced in the treated sperm and the MMPs were largely reduced. The introduction of CoQ10 at concentrations of 20 and 30 µM resulted in a significant rescue of progressive motility (P < 0.05). The result suggested that excessive ROS could be the major cause of sperm motility impairment, likely by damaging mitochondrial energy generation. Autophagy was significantly activated in sperm when they were under oxidative stress, as evidenced by the upregulation of p62 and the increased conversion of LC3 as well as the upregulation of several autophagy-related proteins, such as charged multivesicular body protein 2a, mitochondrial import receptor subunit TOM22 homolog, and WD repeat domain phosphoinositide-interacting protein 2. Additionally, fluorescent staining indicated the occurrence of apoptosis and necrosis in both H2O2-treated sperm and post-thaw sperm. The cell death process can be suppressed when CoQ10 is introduced, which consolidates the view that ROS could be the major contributor to sperm cryoinjury. The freeze-thaw process could also initiate sperm premature capacitation, demonstrated by the prominent increase in tyrosine phosphorylated proteins, verified with anti-phosphotyrosine antibody and immunofluorescence assays. The upregulation of capacitation-related proteins, such as hyaluronidase 3 and Folate receptor alpha, supported this finding. LARGE SCALE DATA: The data underlying this article are available in the article and its online supplementary material. LIMITATIONS, REASONS FOR CAUTION: The semen samples were obtained exclusively from young, healthy, and fertile males with progressive motility exceeding 60%, which might overemphasize the positive effects while possibly neglecting the negative impacts of cryoinjury. Additionally, the H2O2 treatment conditions in this study may not precisely mimic the oxidative stress experienced by sperm after thawing from cryopreservation, potentially resulting in the omission of certain molecular alterations. WIDER IMPLICATIONS OF THE FINDINGS: This study provides substantial proteomic data for a comprehensive and deeper understanding of the impact of cryopreservation on sperm quality. It will facilitate the design of optimal protocols for utilizing cryopreserved sperm to improve applications, such as ART, and help resolve various adverse situations caused by chemotherapy, radiotherapy, and surgery. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by grants from the Major Innovation Project of Research Institute of National Health Commission (#2022GJZD01-3) and the National Key R&D Program of China (#2018YFC1003600). All authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Combined effects of cadmium and simulated acid rain on soil microbial communities in the early cultivation of Populus beijingensis seedlings.

The combined cadmium (Cd) and acid rain pollution poses a significant threat to the global ecological environment. Previous studies on the combined adverse effects have predominantly focused on the aboveground plant physiological responses, with limited reports on the microbial response in the rhizosphere soil. This study employed Populus beijingensis seedlings and potting experiments to simulate the impacts of combined mild acid rain (pH=4.5, MA) or highly strong acid rain (pH=3.0, HA), and soil Cd pollution on the composition and diversity of microbial communities, as well as the physiochemical properties in the rhizosphere soil. The results showed that Cd decreased the content of inorganic nitrogen, resulting in an overall decrease of 49.10 % and 46.67 % in ammonium nitrogen and nitrate nitrogen, respectively. Conversely, acid rain was found to elevate the content of total potassium and soil organic carbon by 4.68 %-6.18 % and 8.64-19.16 %, respectively. Additionally, simulated acid rain was observed to decrease the pH level by 0.29-0.35, while Cd increased the pH level by 0.11. Moreover, Cd alone reduced the rhizosphere bacterial diversity, however, when combined with acid rain, regardless of its intensity, Cd was observed to increase the diversity. Fungal diversity was not influenced by the acid rain, but Cd increased fungal diversity to some extend under HA as observed in bacterial diversity. In addition, composition of the rhizosphere bacterial community was primarily influenced by the inorganic nitrogen components, while the fungal community was driven mainly by soil pH. Furthermore, "Metabolism" was emerged as the most significant bacterial function, which was markedly affected by the combined pollution, while Cd pollution led to a shift from symbiotroph to other trophic types for fungi. These findings suggest that simulated acid rain has a mitigating effect on the diversity of rhizosphere bacteria affected by Cd pollution, and also alters the trophic type of these microorganisms. This can be attributed to the acid rain-induced direct acidic environment, as well as the indirect changes in the availability or sources of carbon, nitrogen, or potassium.

Active Enrichment of Nanoparticles for Ultra-Trace Point-of-Care COVID-19 Detection.

Active enrichment can detect nucleic acid at ultra-low concentrations without relatively time-consuming polymerase chain reaction (PCR), which is an important development direction for future rapid nucleic acid detection. Here, we reported an integrated active enrichment platform for direct hand-held detection of nucleic acid of COVID-19 in nanoliter samples without PCR. The platform consists of a capillary-assisted liquid-carrying system for sampling, integrated circuit system for ultrasound output, and cell-phone-based surface-enhanced Raman scattering (SERS) system. Considering the acoustic responsiveness and SERS-enhanced performance, gold nanorods were selected for biomedical applications. Functionalized gold nanorods can effectively capture and enrich biomarkers under ultrasonic aggregation. Such approaches can actively assemble gold nanorods in 1-2 s and achieved highly sensitive (6.15 × 10-13 M) SERS detection of COVID-19 biomarkers in nanoliter (10-7 L) samples within 5 min. We further demonstrated the high stability, repeatability, and selectivity of the platform, and validated its potential for the detection of throat swab samples. This simple, portable, and ultra-trace integrated active enrichment detection platform is a promising diagnostic tool for the direct and rapid detection of COVID-19.

Internet gaming disorder and tobacco use disorder share neural connectivity patterns between the subcortical and the motor network.

Internet gaming disorder (IGD) and tobacco use disorder (TUD) are globally common, non-substance-related disorders and substance-related disorders worldwide, respectively. Recognizing the commonalities between IGD and TUD will deepen understanding of the underlying mechanisms of addictive behavior and excessive online gaming. Using node strength, 141 resting-state data were collected in this study to compute network homogeneity. The participants included participants with IGD (PIGD: n = 34, male = 29, age: 15-25 years), participants with TUD (PTUD: n = 33, male = 33, age: 19-42 years), and matched healthy controls (control-for-IGD: n = 41, male = 38, age: 17-32 years; control-for-TUD: n = 33, age: 21-27 years). PIGD and PTUD exhibited common enhanced node strength between the subcortical and motor networks. Additionally, a common enhanced resting-state functional connectivity (RSFC) was found between the right thalamus and right postcentral gyrus in PIGD and PTUD. Node strength and RSFC were used to distinguish PIGD and PTUD from their respective healthy controls. Interestingly, models trained on PIGD versus controls could classify PTUD versus controls and vice versa, suggesting that these disorders share common neurological patterns. Enhanced connectivity may indicate a greater association between rewards and behaviors, inducing addiction behaviors without flexible and complex regulation. This study discovered that the connectivity between the subcortical and motor networks is a potential biological target for developing addiction treatment in the future.

Distinct brain activity alterations of treatment for bipolar disorders with psychotherapy and drug therapy: activation likelihood estimation meta-analysis.

BACKGROUNDS: Many studies suggest that both psychotherapy and drug therapy are effective in the treatment of bipolar disorders (BDs). However, the pathophysiology of both types of intervention has not been established definitively. METHODS: An activation likelihood estimation meta-analysis was performed to identify the distinct brain activity alterations between psychotherapy and drug therapy for the treatment of BDs. Articles were identified by searching databases including PubMed, Embase, Cochrane Library, and Web of Science databases. Eligible studies on BDs were published up until 10 June 2021. RESULTS: 21 studies were included and we conducted a meta-analysis for different therapies and imaging tasks. After receiving psychotherapy, BD patients showed increased activation in the inferior frontal gyrus (IFG) and superior temporal gyrus. While after taking drug therapy, BD patients displayed increased activation in the anterior cingulate cortex, medial frontal gyrus, IFG, and decreased activation in the posterior cingulate cortex. The regions of brain activity changes caused by psychotherapy were mostly focused on the frontal areas, while drug therapy mainly impacted on the limbic areas. Different type of tasks also affected brain regions which were activated. CONCLUSIONS: Our comprehensive meta-analysis indicates that these two treatments might have effect on BD in their own therapeutic modes. Psychotherapy might have a top-down effect, while drug therapy might have a bottom-up effect. This study may contribute to differential diagnosis of BDs and would be helpful to finding more accurate neuroimaging biomarkers for BD treatment.

Cognitive behavior therapy for depression in people with epilepsy: A systematic review and meta-analysis.

BACKGROUND: Cognitive behavioral therapy (CBT) is the recommended treatment for depression in patients with epilepsy (PWE). However, there are no studies that calculate the effect size of CBT on depression and quality of life (QoL) in PWE. METHODS: We searched seven electronic databases (PubMed, Web of Science, Embase, Cochrane Library, Clinical Trials, Ovid Medline, and PsycINFO). We included 13 studies examining CBT for depression in PWE and calculated its effect size. RESULTS: A total of 13 studies met the criteria. After treatment, CBT improves depression in PWE (g = 0.36, 95%CI: 0.18 to 0.54, I2 = 50%), and the efficacy maintains during follow-up (g = 0.47, 95%CI: 0.04 to 0.89, I2 = 80%). Subgroup analysis has shown that individual CBT (g = 0.47, 95%CI: 0.20 to 0.73, I2 = 0%) had a greater effect size than group CBT (g = 0.30, 95%CI: 0.07 to 0.53, I2 = 62%) in the treatment of depression. Likewise, CBT has a positive effect on the QoL improvement of PWE (g = 0.34, 95%CI: 0.11 to 0.57, I2 = 64%). In controlling seizures, CBT did not differ from the control group (g = -0.06, 95%CI: -0.32 to 0.19, I2 = 0%). CONCLUSIONS: Cognitive behavioral therapy interventions were effective in improving depression and QoL in PWE, but not effective in controlling seizures. The efficacy of CBT interventions targeting seizure control seems to be uncertain.

The efficacy of schema therapy for personality disorders: a systematic review and meta-analysis.

OBJECTIVE: Personality disorders (PDs) are prevalent and associated with functional impairment and psychological disability. Studies suggest that schema therapy (ST) may be an effective treatment for PDs. This review aimed to evaluate the efficacy of ST in treating PDs. METHOD: We conducted a comprehensive literature search using PubMed, Embase, Web of Science, CENTRAL, PsycInfo, and Ovid Medline. We identified eight randomized controlled trials (587 participants) and seven single-group trials (163 participants). RESULTS: Meta-analyses revealed that ST had a moderate effect size (g = 0.359) compared to control conditions in reducing symptoms of PDs. Subgroup analysis indicated that the effect of ST on different types of PDs varied slightly, and that group ST (g = 0.859) was more effective than individual ST (g = 0.163) in treating PDs. Secondary outcome analysis revealed a moderate effect size (g = 0.256) for ST compared to control conditions in improving quality of life, and ST was found to reduce early maladaptive schema (g = 0.590). Single-group trials analysis showed that ST had a positive effect on PDs (OR = 0.241). CONCLUSION: ST appears to be an effective treatment for PDs, as it reduces symptoms and improves quality of life. This review provides support for the use of ST in the treatment of PDs.

No smoking signs with strong smoking symbols induce weak cravings: an fMRI and EEG study.

No smoking signs (NSSs) that combine smoking symbols (SSs) and prohibition symbols (PSs) represent common examples of reward and prohibition competition. To evaluate how SSs within NSSs influence their effectiveness in guiding reward vs. prohibition, we studied 93 male smokers. We collected self-reported craving ratings (N=30), cue reactivity under fMRI/EEG (N=33), and smoking-behavior anticipation for paired NSSs and SSs (N=30). We found that NSS-induced cravings were negatively correlated with SS-induced cravings and PS-induced inhibition. fMRI indicated that both correlations were mediated by activation of the inferior frontal gyrus and precuneus, suggesting that the effects of SSs and PSs interact with each other. EEG revealed that the prohibition response occurs after the cigarette response, indicating that the cigarette response might be precluded by the prohibition, supporting the effect of SSs in discouraging smoking. Moreover, stronger SSs induced stronger slow positive waves and late positive potentials, and the stronger the late positive potentials, the stronger the late positive potentials. Both the amplitudes of late positive potentials and slow positive waves were positively correlated with the amplitude of N2, which was positively correlated with the attention grabbed score by the NSS. In addition, the weaker the NSS-induced craving, the greater the smoking behavior anticipation reduction, indicating the capability of NSSs to decrease smoking behavior. Our study provides empirical evidence for selecting the most effective NSSs: those combining strong SS and PS, offering insights about competition between cigarette reward and prohibition and providing neural evidence on how cigarette reward and prohibition interact.

Enhanced Isothermal Amplification for Ultrafast Sensing of SARS-CoV-2 in Microdroplets.

Rapid and high-throughput screening is critical to control the COVID-19 pandemic. Recombinase polymerase amplification (RPA) with highly accessible and sensitive nucleic acid amplification has been widely used for point-of-care infection diagnosis. Here, we report an integrated microdroplet array platform composed of an ultrasonic unit and minipillar array to enhance the RPA for ultrafast, high-sensitivity, and high-throughput detection of SARS-CoV-2. On such a platform, the independent microvolume reactions on individual minipillars greatly decrease the consumption of reagents. The microstreaming driven by ultrasound creates on-demand contactless microagitation in the microdroplets and promotes the interaction between RPA components, thus greatly accelerating the amplification. In the presence of microstreaming, the detection time is 6-12 min, which is 38.8-59.3% shorter than that of controls without microstreaming, and the end-point fluorescence intensity also increased 1.3-1.7 times. Furthermore, the microagitation-enhanced RPA also exhibits a lower detection limit (0.42 copy/µL) for SARS-CoV-2 in comparison to the controls. This integrated microdroplet array detection platform is expected to meet the needs for high-throughput nucleic acid testing (NAT) to improve the containment of viral transmission during the epidemic, as well as provide a potential platform for the timely detection of other pathogens or viruses.

Suitable coverage and slope guided by soil and water conservation can prevent non-point source pollution diffusion: A case study of grassland.

Non-point source pollution caused by surface runoff has been a popular hydrological and environmental safety issue and has attracted extensive attention from global scholars. To identify the optimal vegetation coverage of Festuca arundinacea grassland for controlling soil erosion and purifying surface runoff, bare land was chosen as the control in this experiment. Simulated rainfall experiments were carried out with three levels of coverage (low coverage, moderate coverage and full coverage) under four slope conditions (flat slope, gentle slope, medium slope, and steep slope) and at four rainfall intensities (moderate rainfall, heavy rainfall, rainstorm and heavy rainstorm). The comprehensive evaluation results suggested that the capacity of Festuca arundinacea grassland for reducing the surface runoff, sediment yield, suspended solids (SS), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) decreased with increasing rainfall intensity and slope but increased with increasing vegetation coverage. Structural equation model (SEM) results suggested that there were positive relationships between the vegetation coverage and purification capacity index and negative correlations between the rainfall intensity and slope and the purification capacity index. The response surface analysis results suggested that the optimal vegetation coverage should be higher than 84% and that the slope should be smaller than 10° for controlling soil erosion and avoiding pollution via diffusion with surface runoff in Festuca arundinacea grassland. This study proposes recommendations for the vegetation configuration pattern in the development and management of runoff purification systems.

Cyclosporin A Inhibits the Activation of Membrane-Bound Guanylate Cyclase GC-A of Atrial Natriuretic Factor via NAD(P)H Oxidase.

Cyclosporin A (CsA) is a common immunosuppressant wildly used in patients with organ transplant and autoimmune diseases; however, it can cause several adverse effects, such as nephrotoxicity and hypertension. The detailed mechanisms have not been completely understood. Atrial natriuretic factor (ANF) and its receptor (mGC-A) have been shown to play a crucial role in the regulation of blood pressure. Here, we investigated the effects of CsA on the activation of mGC-A in ANF-treated LLC-PK1 cells. In our study, ANF-induced mGC-A activities and superoxide generation in LLC-PK1 cells were measured by guanosine 3',5'-cyclic monophosphate (cGMP) radioimmunoassay and lucigenin-dependent chemiluminescence, respectively. We found that CsA can reduce about 60% of mGC-A activities in ANF-treated LLC-PK1 cells. CsA is known to induce superoxide. Addition of superoxide generators menadione and diamide mimicked the effects of CsA, whereas DPI (a reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase inhibitor) and Tiron (a superoxide quencher) blocked the suppressive effects of CsA on ANF-induced mGC-A activities. We previously showed that the catalytic domain of GC-A (GC-c) expresses guanylate cyclase activities. Addition of menadione, diamide, or peroxynitrite or transfection of Nox-4 NAD(P)H oxidase abolished GC-c activities. In conclusion, CsA inhibits ANF-stimulated mGC-A activities through superoxide and/or peroxynitrite generated by an NAD(P)H oxidase by interacting with the catalytic domain of mGC-A.

Biospired Janus Silk E-Textiles with Wet-Thermal Comfort for Highly Efficient Biofluid Monitoring.

Functionalized textiles capable of biofluid administration are favorable for enhancing the wet-thermal comfort of the wearer and healthcare performance. Herein, inspired by the Janus wettability of lotus leaf, we propose a skin-comfortable Janus electronic textile (e-textile) based on natural silk materials for managing and analysis of biofluid. Silk materials are chosen and modified as both a textile substrate and a sensing electrode due to its natural biocompatibility. The unidirectional biofluid behavior of such Janus silk substrate facilitates a comfortable skin microenvironment, including weakening the undesired wet adhesion (∼0 mN cm-2) and avoiding excessive heat or cold on the epidermis. We noninvasively analyze multiple targets of human sweat with less required liquid volume (∼5 µL) and a faster (2-3 min) response time based on the silk-based yarn electrode woven into the hydrophilic side of Janus silk. This work bridges the gap between physiological comfort and sensing technology using biomass-derived elements, presenting a new type of smart textiles for wet-thermal management and health monitoring.

Identification of a lncRNA prognostic signature-related to stem cell index and its significance in colorectal cancer.

Background: The relationship between long noncoding RNAs (lncRNAs) and the mRNA stemness index (mRNAsi) in colorectal cancer (CRC) is still unclear. Materials & methods: The mRNAsi, mRNAsi-related lncRNAs and their clinical significance were analyzed by bioinformatic approaches in The Cancer Genome Atlas (TCGA)-COREAD dataset. Results: mRNAsi was negatively related to pathological features but positively related to overall survival and recurrence-free survival in CRC. A five mRNAsi-related lncRNAs prognostic signature was further developed and showed independent prognostic factors related to overall survival in CRC patients, due to the five mRNAsi-related lncRNAs involved in several pathways of the cancer stem cells and malignant cancer cell phenotypes. Conclusion: The present study highlights the potential roles of mRNAsi-related lncRNAs as alternative prognostic markers.

Lay abstract Previous evidence has indicated that the mRNA stem index (mRNAsi) is representative of the stemness of cancer stem cells (CSCs), whereas long noncoding RNAs (lncRNAs) may be crucial regulators in CSC phenotype. Nevertheless, the relationship between lncRNAs and mRNAsi in CRC is still unclear. Our results show that the mRNAsi was negatively related to pathological features and positively related to prognosis in CRC. Five mRNAsi-related lncRNAs were further identified and developed as a prognostic signature that could independently predict survival in CRC patients due to the five mRNAsi-related lncRNAs being involved in several pathways of CSCs and malignant cancer cell phenotypes, indicating the potential roles of mRNAsi-related lncRNAs as alternative prognostic markers.

A terbium(III)-functionalized zinc(II)-organic framework for fluorometric determination of phosphate.

A terbium(III)-functionalized zinc(II)-organic framework (Tb-MOF-Zn) is shown to be a viable fluorescent probe for phosphate. The organic ligands 4,4',4″-[((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene))tris(oxy)]tribenzoic acid (H3L3) contains multiple carboxyl groups that can react with zinc(II) to yield tubular MOF-Zn. The MOF-Zn was further functionalized with Tb(III) to produce a lanthanide composite of type Tb-MOF-Zn which displays strong fluorescence with excitation/emission maxima at 285/544 nm. Fluorescence is quenched by phosphate because of the specific interaction with Tb(III) in Tb-MOF-Zn. The concentration of Tb-MOF-Zn, reaction time and pH value of the solution were optimized. Fluorescence drops linearly in the 0.01 to 200.0 µM phosphate concentration range, and the detection limit is 4.0 nM. The fluorescent probe was also used to prepare a microdot array on a glass slide for visual detection of phosphate under illumination with UV light. Graphical abstractA terbium(III) functionalized zinc(II)-organic framework was synthesized and used as fluorescent probe for determination of phosphate ions.

High ANKZF1 expression is associated with poor overall survival and recurrence-free survival in colon cancer.

Aim: To investigate the association and prognostic value of ANKZF1 gene for survival in colorectal cancer, the mechanism of ANKZF1 level alteration and correlated signaling pathways ANKZF1 is involved. Patients & methods: The Cancer Genome Atlas COREAD dataset was analyzed by bioinformatical investigation. Results: High ANKZF1 expression is associated with poor overall survival (hazard ratio [HR]: 2.094; 95% CI: 1.188-3.689; p = 0.011) and recurrence-free survival (HR: 1.762; 95% CI: 1.021-3.042; p = 0.042) in colon cancer. Bioinformatical analysis showed ANKZF1 was upregulated by amplification and exon expression. ANKZF1 was associated with angiogenesis and cancer signaling pathways. Conclusion: High ANKZF1 is an independent factor of poor survival (overall survival and recurrence-free survival) in colon cancer by taking part in angiogenesis and some cancer signaling pathways.

Polyhydric polymer-loaded pyrene composites as powerful adsorbents and fluorescent probes: highly efficient adsorption and test strips-based fluorimetric analysis of curcumin in urine and plant extracts.

Polyhydric poly (vinyl alcohol) was covalently loaded with a 1-pyrenecarboxyaldehyde fluorophore. The yielded PVA-Pyr composites can serve as powerful adsorbents and strong fluorescent probes for the highly efficient adsorption and sensitive fluorimetric detection with test strips of curcumin in samples of urine and plant extracts.

Multicomponent Self-Assembled Metal-Organic [3]Rotaxanes.

A set of environmentally responsive metal-organic [3]rotaxanes is described. These mechanically interlocked macromolecules may be prepared in quantitative yield via a one-pot procedure involving treatment of a flexible tetracationic macrocycle, known as the Texas-sized molecular box, with tri-1,3,5-benzenetricarboxylate anion and silver cations (Ag(+)). The use of this three-component mixture gives rise to a metal-organic [3]rotaxane via a self-assembly process that occurs under ambient conditions in DMSO-d6 solution. The complex is stable in the presence of excess TFA. However, disassembly of the [3]rotaxane to produce anion-box associated entities may be triggered by adding a competitive counteranionic species (e.g., I(-)). Adding excess Ag(+) serves to reverse this decomplexation process. The nature of the [3]rotaxane complex could be fine-tuned via application of an external stimulus. Increasing the temperature or adding small molecules (e.g., D2O, methanol-d4, acetonitrile-d3, DMF-d7, acetone-d6, or THF-d8) to the initial DMSO-d6 solution induces conformational flipping of the macrocycle within the overall complex (e.g., from limiting chair to chairlike forms). Support for the molecular stimuli responsive nature of the various structures came from solution-phase one- and two-dimensional ((1)H, 1D and 2D NOESY) NMR spectroscopic studies carried out in DMSO-d6. The core metal-linked rotaxane unit was characterized via single-crystal X-ray diffraction analysis. Initial evidence that the present self-assembly process is not limited to the use of the Ag(+) cation came from studies involving Cd(2+); this replacement results in formation of 2D metal-organic rotaxane-containing frameworks (MORFs).

Ubiquitin-dependent regulation of phospho-AKT dynamics by the ubiquitin E3 ligase, NEDD4-1, in the insulin-like growth factor-1 response.

AKT is a critical effector kinase downstream of the PI3K pathway that regulates a plethora of cellular processes including cell growth, death, differentiation, and migration. Mechanisms underlying activated phospho-AKT (pAKT) translocation to its action sites remain unclear. Here we show that NEDD4-1 is a novel E3 ligase that specifically regulates ubiquitin-dependent trafficking of pAKT in insulin-like growth factor (IGF)-1 signaling. NEDD4-1 physically interacts with AKT and promotes HECT domain-dependent ubiquitination of exogenous and endogenous AKT. NEDD4-1 catalyzes K63-type polyubiquitin chain formation on AKT in vitro. Plasma membrane binding is the key step for AKT ubiquitination by NEDD4-1 in vivo. Ubiquitinated pAKT translocates to perinuclear regions, where it is released into the cytoplasm, imported into the nucleus, or coupled with proteasomal degradation. IGF-1 signaling specifically stimulates NEDD4-1-mediated ubiquitination of pAKT, without altering total AKT ubiquitination. A cancer-derived plasma membrane-philic mutant AKT(E17K) is more effectively ubiquitinated by NEDD4-1 and more efficiently trafficked into the nucleus compared with wild type AKT. This study reveals a novel mechanism by which a specific E3 ligase is required for ubiquitin-dependent control of pAKT dynamics in a ligand-specific manner.

Identification and characterization of a chondroitinase ABC with a novel carbohydrate-binding module.

Chondroitinases play important roles in structural and functional studies of chondroitin sulfates. Carbohydrate-binding module (CBM) is generally considered as an accessory module in carbohydrate-active enzymes, which promotes the association of the appended enzyme with the substrate and potentiates the catalytic activity. However, the role of natural CBM in chondroitinases has not been investigated. Herein, a novel chondroitinase ChABC29So containing an unknown domain with a predicted ß-sandwich fold was discovered from Segatella oris. Recombinant ChABC29So showed enzyme activity towards chondroitin sulfates and hyaluronic acid and acted in a random endo-acting manner. The unknown domain exhibited a chondroitin sulfate-binding capacity and was identified as a CBM. Biochemical characterization of ChABC29So and the CBM-truncated enzyme revealed that the CBM enhances the catalytic activity, thermostability, and disaccharide proportion in the final enzymatic products of ChABC29So. These findings demonstrate the role of the natural CBM in a chondroitinase and will guide future modification of chondroitinases.