Conductive polymers (CPs) are promising organic semiconductors for many essential applications because of their tunable physical/chemical properties, mechanical flexibility, low weight, reversible ...doping, good biocompatibility, and scalable production. However, CPs have not achieved their expected application potential in conventional processing methods. Electrospinning is a simple and highly versatile technique that can be used for mass fabrication of continuous ultrafine fibers from various polymers and composites. Electrospun fibers have many advantages, including uniformity, porosity, large surface areas, and mechanical strength, which present new application areas of CPs, and solve a number of problems related to the applicability of the polymers. However, as CPs are soluble and brittle, electrospinning requires a specific strategy. Different approaches, including direct electrospinning of CPs into fibers, co-electrospinning of blends of CPs and other spinnable carrier polymers, and synthesizing of electrospun fiber-template, have been developed to solve this problem. In this review, the recent achievements of fabricating CP-based ultrafine fibers using an electrospinning process are summarized, along with the characterization of their physical–chemical properties, such as electrical conductivity, wettability, and mechanical and thermal properties, which are further improved by modification. More emphasis is placed on the potential applications of electrospun CP ultrafine fibers in bio-/chemical sensors, artificial muscles, neural electrodes/interfaces, tissue regeneration, controlled drug release, flexible/stretchable electronic devices, energy storage, and electromagnetic interference shielding materials. Furthermore, the current challenges and future opportunities are also addressed.
The homeostatic link between oxidative stress and autophagy plays an important role in cellular responses to a wide variety of physiological and pathological conditions. However, the regulatory ...pathway and outcomes remain incompletely understood. Here, we show that reactive oxygen species (ROS) function as signaling molecules that regulate autophagy through ataxia‐telangiectasia mutated (ATM) and cell cycle checkpoint kinase 2 (CHK2), a DNA damage response (DDR) pathway activated during metabolic and hypoxic stress. We report that CHK2 binds to and phosphorylates Beclin 1 at Ser90/Ser93, thereby impairing Beclin 1‐Bcl‐2 autophagy‐regulatory complex formation in a ROS‐dependent fashion. We further demonstrate that CHK2‐mediated autophagy has an unexpected role in reducing ROS levels via the removal of damaged mitochondria, which is required for cell survival under stress conditions. Finally, CHK2−/− mice display aggravated infarct phenotypes and reduced Beclin 1 p‐Ser90/Ser93 in a cerebral stroke model, suggesting an in vivo role of CHK2‐induced autophagy in cell survival. Taken together, these results indicate that the ROS‐ATM‐CHK2‐Beclin 1‐autophagy axis serves as a physiological adaptation pathway that protects cells exposed to pathological conditions from stress‐induced tissue damage.
Synopsis
Whether hypoxia and nutrient starvation are coupled to cellular autophagy remains unclear. Here, DNA damage response kinases ATM and CHK2 are shown to trigger autophagy in response to reactive oxygen species (ROS) accumulation, suggesting a novel physiological adaptation pathway toward metabolic stress.
Depletion of CHK2 or ATM impairs oxidative stress‐induced autophagy in MEFs.
CHK2 binds and phosphorylates Beclin1 at Ser90/Ser93, suppressing Beclin1‐Bcl‐2 autophagy regulatory complex formation.
CHK2‐induced autophagy limits intracellular ROS levels by clearing damaged mitochondria.
CHK2‐induced autophagy protects against cell death and tissue damage following cerebral ischemia.
ROS accumulation activates protective autophagy to prevent stress‐induced tissue damage.
Electrospinning is a straightforward and versatile method to fabricate ultrafine fibers with unique physical and chemical properties. However, the chaotic nature of traditional electrospinning limits ...its applications in devices which usually need arranged or patterned micro/nanoscale fibrous structures. In order to improve the controllable deposition of electrospun fibers, near-field electrospinning (NFES) has been proposed and developed in recent years. With characteristics of position-controlled deposition, NFES significantly expands the range of fiber-fabrication uses including electronic components, energy harvesting, flexible sensors, and tissue engineering. In this paper, the basic principle and research advances of NFES have been briefly reviewed. In particular, we summarize the process parameters, polymer materials, as-spun fibrous structures, modified apparatus, and potential applications of NFES. Finally, future prospects on the development tendency and challenges of NFES are discussed.
METTL3 catalyzes the formation of N
-methyl-adenosine (m
A) which has important roles in regulating various biological processes. However, the in vivo function of Mettl3 remains largely unknown in ...mammals. Here we generated germ cell-specific Mettl3 knockout mice and demonstrated that Mettl3 was essential for male fertility and spermatogenesis. The ablation of Mettl3 in germ cells severely inhibited spermatogonial differentiation and blocked the initiation of meiosis. Transcriptome and m
A profiling analysis revealed that genes functioning in spermatogenesis had altered profiles of expression and alternative splicing. Our findings provide novel insights into the function and regulatory mechanisms of Mettl3-mediated m
A modification in spermatogenesis and reproduction in mammals.
Growing evidence has shown that alterations in gut microbiota composition are associated with multiple autoimmune diseases (ADs). However, it is unclear whether these associations reflect a causal ...relationship.
To reveal the causal association between gut microbiota and AD, we conducted a two-sample Mendelian randomization (MR) analysis.
We assessed genome-wide association study (GWAS) summary statistics for gut microbiota and six common ADs, namely, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, type 1 diabetes (T1D), and celiac disease (CeD), from published GWASs. Two-sample MR analyses were first performed to identify causal bacterial taxa for ADs in discovery samples. Significant bacterial taxa were further replicated in independent replication outcome samples. A series of sensitivity analyses was performed to validate the robustness of the results. Finally, a reverse MR analysis was performed to evaluate the possibility of reverse causation.
Combining the results from the discovery and replication stages, we identified one causal bacterial genus,
. A higher relative abundance of the
genus was associated with a higher risk of T1D odds ratio (OR): 1.605; 95% CI, 1.339-1.922;
= 4.19 × 10
and CeD (OR: 1.401; 95% CI, 1.139-1.722;
= 2.03 × 10
), respectively. Further sensitivity analyses validated the robustness of the above associations. The results of reverse MR analysis showed no evidence of reverse causality from T1D and CeD to the
genus.
This study implied a causal relationship between the
genus and T1D and CeD, thus providing novel insights into the gut microbiota-mediated development mechanism of ADs.
Breast cancer is one the most common cancers, making it the second leading cause of cancer-related death among women. Long non-coding RNAs (lncRNAs), with tightly regulated expression patterns, also ...serve as tumor suppressor during tumorigenesis. The present study aimed to elucidate the role of LINC00968 in breast cancer via WNT2-mediated Wnt2/β-catenin signaling pathway.
Breast cancer chip GSE26910 was utilized to identify differential expression in LINC00968 and WNT2. The possible relationship among LINC00968, transcriptional repressor HEY and WNT2 was analyzed and then verified. Effects of LINC00968 on activation of the Wnt2/β-catenin signaling pathway was also tested. Drug resistance, colony formation, cell migration, invasion ability and cell apoptosis after transfection were also determined. Furthermore, tumor xenograft in nude mice was performed to test tumor growth and weight in vivo.
WNT2 expression exhibited at a high level, whereas LINC00968 at a low expression in breast cancer which was also associated with poor prognosis in patients. LINC00968 targeted and negatively regulated WNT2 potentially via HEY1. Either overexpressed LINC00968 or silenced inhibited activation of the Wnt2/β-catenin signaling pathway, thereby reducing drug resistance, decreasing colony formation ability, as well as suppressing migration and invasion abilities of breast cancer cells in addition to inducing apoptosis. Lastly, in vivo experiment suggested that LINC00968 overexpression also suppressed transplanted tumor growth in nude mice.
Collectively, overexpressed LINC00968 contributes to reduced drug resistance in breast cancer cells by inhibiting the activation of the Wnt2/β-catenin signaling pathway through silencing WNT2. This study offers a new target for the development of breast cancer treatment.
Electrospinning (e‐spinning) has been extensively explored as a simple, versatile, and cost‐effective method in preparing ultrathin fibers from a wide variety of materials. Electrospun (e‐spun) ...ultrathin fibers are now widely used in tissue scaffold, wound dressing, energy harvesting and storage, environment engineering, catalyst, and textile. However, compared with conventional fiber industry, one major challenge associated with e‐spinning technology is its production rate. Over the last decade, compared with conventional needle e‐spinning, needleless e‐spinning has emerged as the most efficient strategy for large‐scale production of ultrathin fibers. For example, rolling cylinder and stationary wire as spinnerets have been commercialized successfully for significantly improving throughput of e‐spun fibers. The significant advancements in needleless e‐spinning approaches, including spinneret structures, productivity, and fiber quality are reviewed. In addition, some striking examples of innovative device designs toward higher throughput, as well as available industrial‐scale equipment and commercial applications in the market are highlighted.
Needleless electrospinning has emerged as the most efficient strategy for large‐scale producing ultrathin fibers, which can offer actual opportunities both for laboratory research and industrial production. In this review, the significant advancements in needleless electrospinning approaches and strategies are discussed.
Theory and experiments support that plant invasions largely impact aboveground biodiversity and function. Yet, much less is known on the influence of plant invasions on the structure and function of ...the soil microbiome of coastal wetlands, one of the largest major reservoirs of biodiversity and carbon on Earth. We studied the continental‐scale invasion of Spartina alterniflora across 2451 km of Chinese coastlines as our model‐system and found that S. alterniflora invasion can largely influence the soil microbiome (across six depths from 0 to 100 cm), compared with the most common microhabitat found before invasion (mudflats, Mud). In detail, S. alterniflora invasion was not only positively associated with bacterial richness but also resulted in important biotic homogenization of bacterial communities, suggesting that plant invasion can lead to important continental scale trade‐offs in the soil microbiome. We found that plant invasion changed the community composition of soil bacterial communities across the soil profile. Moreover, the bacterial communities associated with S. alterniflora invasions where less responsive to climatic changes than those in native Mud microhabitats, suggesting that these new microbial communities might become more dominant under climate change. Plant invasion also resulted in important reductions in the complexity and stability of microbial networks, decoupling the associations between microbes and carbon pools. Taken together, our results indicated that plant invasions can largely influence the microbiome of coastal wetlands at the scale of China, representing the first continental‐scale example on how plant invasions can reshuffle the soil microbiome, with consequences for the myriad of functions that they support.
The continental‐scale invasion of Spartina alterniflora across China’s coastline was used as our model‐system to study the impact of plant invasions on the soil microbiome of blue carbon ecosystems. Plant invasion led to important trade‐offs in the soil microbiome by promoting bacterial richness, while resulting in biotic homogenization of bacterial communities. Plant invasion was further associated with an important reduction in the complexity and stability of microbial networks, and resulted in an important decoupling between soil microbes and carbon pools.
A network meta‐analysis was conducted to compare the short‐term efficacy and adverse events of different drugs for the treatment of postmenopausal osteoporosis (PMO), providing a more effective ...treatment for PMO. We initially searched through various databases like PubMed, Cochrane Library, and EMBASE from inception till October 2016. All randomized controlled trials (RCTs) of drugs for the treatment of PMO were included for direct and indirect comparison. A combination of direct and indirect evidence of different inhibitors of anti‐diabetic drugs for treatment of PMO were considered for calculating the weighted mean difference (WMD) value or odd ratio (OR) value and to draw surface under the cumulative ranking (SUCRA) curves. Twenty‐seven RCTs were ultimately incorporated into this network meta‐analysis comprising of 48 200 patients suffering from PMO. The network meta‐analysis revealed that compared with placebo, alendronate had better efficacy on improving bone mineral density (BMD) at lumbar spine, femoral neck, and total hip. Risedronate and raloxifene had relatively lower incidence of new vertebral fractures. The SUCRA analysis showed that alendronate had better efficacy on improving BMD, risedronate could significantly decrease the incidence of fresh fracture and bazedoxifene was relatively safe. The available evidence suggested that alendronate and risedronate might be the superior choices for the treatment of PMO, while bazedoxifene was a comparatively safer option for patients.
The available evidence suggested that alendronate and risedronate might be the superior choices for the treatment of PMO, while bazedoxifene was a comparatively safer option for patients.
Evidence supports the observational associations of gut microbiota with a variety of psychiatric disorders, but the causal nature of such associations remains obscure. Aiming to comprehensively ...investigate their causal relationship and to identify specific causal microbe taxa for psychiatric diseases, we conducted a two-sample Mendelian randomization (MR) analysis of gut microbiome with 15 psychiatric diseases. Specifically, the microbiome genome-wide association study (GWAS) in 18,473 individuals from the MiBioGen study was used as exposure sample, and the GWAS for 15 psychiatric diseases was used as outcome samples. One-hundred ninety bacterial taxa from six levels were available for analysis. At a multiple-testing corrected significance level (phylum
< 5.56 × 10
, class
< 3.33 × 10
, order
< 2.63 × 10
, family
< 1.67 × 10
, genus
< 4.90 × 10
, and species
< 3.33 × 10
), the following eight causal associations from seven bacterial features (one phylum + three classes + one order + one family + one species) were identified: family
with autism spectrum disorder (
= 5.31 × 10
), class
with bipolar disorder (
= 1.53 × 10
), class
with schizophrenia (
= 1.33 × 10
), class
and order
with Tourette syndrome (
= 2.51 × 10
and 2.51 × 10
), phylum
and class
with extroversion (
= 8.22 × 10
and 1.09 × 10
), and species
with neuroticism (
= 8.92 × 10
). Sensitivity analysis showed no evidence of reverse causality, pleiotropy, and heterogeneity. Our findings offered novel insights into the gut microbiota-mediated development mechanism of psychiatric disorders.
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