Evaluation of the Protective Bioactivity and Molecular Mechanism Verification of Lactoferrin in an Alzheimer's Mouse Model with Ulcerative Enteritis.

The development of new drug therapies for Alzheimer's disease (AD) is an important research topic today, but the pathogenesis of AD has not been thoroughly studied, and there are still several shortcomings in existing drug therapies. Therefore, this study aims to explore the molecular mechanism of lactoferrin in the treatments of AD and ulcerative colitis (UC) which are susceptible to AD, starting from the principle of "one drug, two diseases, and the same treatment." This study used pathological staining and specific indicators staining to preliminarily evaluate the interventions of lactoferrin on UC injury and AD progression. And 16s RNA full-length sequencing was used to investigate the effect of lactoferrin on the abundance of intestinal microbiota in AD mice. Then, intestinal tissue and brain tissue metabolomics analysis were used to screen specific metabolic pathways and preliminarily verify the metabolic mechanism of lactoferrin in alleviating 2 diseases by regulating certain specific metabolites. Moreover, lactoferrin significantly changed the types and abundance of gut microbiota in AD mice complicated by UC. To conclude, this study proved the clinical phenomenon of AD susceptibility to UC, and verified the therapeutic effect of lactoferrin on 2 diseases. More importantly, we revealed the possible molecular mechanism of LF, not only does it enrich the cognitive level of lactoferrin in alleviating AD by regulating the gut microbiota through the brain gut axis from the perspective of the theory of "food nutrition promoting human health," but it also provides a practical basis for the subsequent research and development of lactoferrin and drug validation from the perspective of "drug food homology."

RNA-based detection of genetically modified plants via current-voltage characteristic measurement.

The widespread adoption of genetically modified (GM) crops has escalated concerns about their safety and ethical implications, underscoring the need for efficient GM crop detection methods. Conventional detection methods, such as polymerase chain reaction, can be costly, lab-bound, and time-consuming. To overcome these challenges, we have developed RapiSense, a cost-effective, portable, and sensitive biosensor platform. This sensor generates a measurable voltage shift (0.1-1 V) in the system's current-voltage characteristics, triggered by an increase in membrane's negative charge upon hybridization of DNA/RNA targets with a specific DNA probe. Probes designed to identify the herbicide resistance gene hygromycin phosphotransferase show a detection range from ∼1 nM to ∼10 µM and can discriminate between complementary, non-specific, and mismatched nucleotide targets. The incorporation of a small membrane sensor to detect fragmented RNA samples substantially improve the platform's sensitivity. In this study, RapiSense has been effectively used to detect specific DNA and fragmented RNA in transgenic variants of Arabidopsis, sweet potato, and rice, showcasing its potential for rapid, on-site GM crop screening.

Spontaneous Threshold Lowering Neuron using Second-Order Diffusive Memristor for Self-Adaptive Spatial Attention.

Intrinsic plasticity of neurons, such as spontaneous threshold lowering (STL) to modulate neuronal excitability, is key to spatial attention of biological neural systems. In-memory computing with emerging memristors is expected to solve the memory bottleneck of the von Neumann architecture commonly used in conventional digital computers and is deemed a promising solution to this bioinspired computing paradigm. Nonetheless, conventional memristors are incapable of implementing the STL plasticity of neurons due to their first-order dynamics. Here, a second-order memristor is experimentally demonstrated using yttria-stabilized zirconia with Ag doping (YSZ:Ag) that exhibits STL functionality. The physical origin of the second-order dynamics, i.e., the size evolution of Ag nanoclusters, is uncovered through transmission electron microscopy (TEM), which is leveraged to model the STL neuron. STL-based spatial attention in a spiking convolutional neural network (SCNN) is demonstrated, improving the accuracy of a multiobject detection task from 70% (20%) to 90% (80%) for the object within (outside) the area receiving attention. This second-order memristor with intrinsic STL dynamics paves the way for future machine intelligence, enabling high-efficiency, compact footprint, and hardware-encoded plasticity.

Chronic remote ischaemic conditioning in patients with symptomatic intracranial atherosclerotic stenosis (the RICA trial): a multicentre, randomised, double-blind sham-controlled trial in China.

BACKGROUND: Intracranial atherosclerotic stenosis (ICAS) is one of the most common causes of stroke worldwide, and it is associated with a high risk of recurrent stroke with currently recommended treatments. We aimed to evaluate the effect of chronic remote ischaemic conditioning on prevention of ischaemic events in patients with symptomatic ICAS. METHODS: The RICA trial is a multicentre, randomised, double-blind, sham-controlled trial at 84 stroke centres in China. Patients aged 40-80 years with ischaemic stroke or transient ischaemic attack attributable to angiographically verified 50-99% stenosis of a major intracranial artery were randomly assigned (1:1), via an interactive web-based system by computer-generated randomisation code, to either remote ischaemic conditioning or sham remote ischaemic conditioning once daily for 12 months and voluntarily thereafter. All investigators and patients were masked to treatment allocation. The primary efficacy endpoint was the time to first occurrence of non-fatal or fatal ischaemic stroke, with survival analysed by the Kaplan-Meier method. Primary and safety analyses were done in the intention-to-treat population. The RICA trial is registered with ClinicalTrials.gov, number NCT02534545. FINDINGS: Between Oct 28, 2015, and Feb 28, 2019, 3033 patients were enrolled and randomly assigned to either remote ischaemic conditioning (n=1517; intervention group) or sham remote ischaemic conditioning (n=1516; sham group). Median follow-up was 3·5 years (IQR 2·7-4·4). A non-fatal or fatal ischaemic stroke occurred in 257 (16·9%) patients in the intervention group compared with 288 (19·0%) patients in sham group. There was no difference in the survival distribution for time to first occurrence of non-fatal or fatal ischaemic stroke (hazard ratio 0·87, 95% CI 0·74-1·03; p=0·12). In the intervention group, 79 (5·2%) patients died from any cause, and in the sham group, 84 (5·5%) patients died from any cause (hazard ratio 0·93, 95% CI 0·68-1·27; p=0·65). No intervention-related serious adverse events were observed. INTERPRETATION: No evidence was found for a difference between remote ischaemic conditioning and sham remote ischaemic conditioning in lowering the risk of ischaemic stroke in patients with symptomatic ICAS. The benefit of remote ischaemic conditioning might have been diluted by poor compliance. Future studies of remote ischaemic conditioning in this population should address challenges in patients' compliance and assess longer term treatment. FUNDING: Ministry of Science and Technology China, Beijing Municipal Education Commission, Beijing Municipal Finance Bureau. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Strongly Improving the Sensitivity of Phosphorescence-Based Optical Oxygen Sensors by Exploiting Nano-Porous Substrates.

Sensitivity is one of the crucial factors in determining the quality of a fluorescence/phosphorescence-based gas sensor, and is estimated from the measurement of responses (I0/I, where I0 and I refer to the measured optical intensity of a sensor in absence and presence of analyte molecules) at various concentrations of analytes. In this work, we demonstrate phosphorescence-based optical oxygen sensors fabricated on highly porous anodic aluminum oxide (AAO) membranes showing dramatically high response. These sensors exploit the enormous surface area of the AAO to facilitate the effective interaction between the sensing molecules and the analytes. We spin-coat an AAO membrane (200 nm pore diameter) with a platinum-based oxygen sensing porphyrin dye, platinum(II) meso-tetrakis (pentafluorophenyl) porphyrin (PtTFPP), to fabricate a sensor exhibiting I0/I ~400 at 100% oxygen atmosphere. To address the generality of the AAO membrane, we fabricate a separate sensor with another porphyrin dye, platinum octaethylporphyrin (PtOEP), which exhibits an even higher I0/I of ~500. Both of these sensors offer the highest responses as an optical oxygen sensor hitherto reported. SEM and EDS analysis are performed to realize the effect of the increased surface area of the AAO membrane on the enhanced sensitivity.

Ingenious Fabrication of Ag-Filled Porous Anodic Alumina Films as Powerful SERS Substrates for Efficient Detection of Biological and Organic Molecules.

Surface-enhanced Raman scattering (SERS) has been widely used to effectively detect various biological and organic molecules. This detection method needs analytes adsorbed onto a specific metal nanostructure, e.g., Ag-nanoparticles. A substrate containing such a structure (called SERS substrate) is user-friendly for people implementing the adsorption and subsequent SERS detection. Here, we report on powerful SERS substrates based on efficient fabrication of Ag-filled anodic aluminum oxide (AAO) films. The films contain many nanopores with small as-grown inter-pore gap of 15 nm. The substrates are created by electrochemically depositing silver into nanopores without an additional pore widening process, which is usually needed for conventional two-step AAO fabrication. The created substrates contain well-separated Ag-nanoparticles with quite a small inter-particle gap and a high number density (2.5 × 1010 cm-2). We use one-step anodization together with omitting additional pore widening to improve the throughput of substrate fabrication. Such substrates provide a low concentration detection limit of 10-11 M and high SERS enhancement factor of 1 × 106 for rhodamine 6G (R6G). The effective detection of biological and organic molecules by the substrate is demonstrated with analytes of adenine, glucose, R6G, eosin Y, and methylene blue. These results allow us to take one step further toward the successful commercialization of AAO-based SERS substrates.

Oscillator-Network-Based Ising Machine.

With the slowdown of Moore's law, many emerging electronic devices and computing architectures have been proposed to sustain the performance advancement of computing. Among them, the Ising machine is a non-von-Neumann solver that has received wide attention in recent years. It is capable of solving intractable combinatorial optimization (CO) problems, which are difficult to be solve using conventional digital computers. In fact, many CO problems can be mapped to finding the corresponding ground states of Ising model. At present, Ising machine prototypes based on different physical principles, such as emerging memristive oscillators, have been demonstrated, among which the Ising Hamiltonian solver based on the coupled oscillator network simultaneously holds the advantages of room-temperature operation, compact footprint, low power consumption, and fast speed to solution. This paper comprehensively surveys the recent developments in this important field, including the types of oscillators, the implementation principle of the Ising model, and the solver's performance. Finally, methods to further improve the performance have also been suggested.

The clinical efficacy and safety of atropine combined with omeprazole in the treatment of patients with acute gastritis: a systematic review and meta-analysis.

BACKGROUND: To date, guidelines on the impact and value of atropine combined with omeprazole in the treatment of acute gastritis have not been well established or well defined. This study aimed to clarify the efficacy and safety of combined atropine and omeprazole therapy for the management of patients with acute gastritis. METHODS: Through searching the electronic database, the related literature of the combination of atropine with omeprazole in the treatment of acute gastritis were reviewed. A meta-analysis was performed after literature selection according to inclusion criteria. The treatment efficiency and the incidence of adverse reactions were used as the main outcome indicators. The odds ratios (ORs), standardized mean differences (SMDs), and 95% confidence intervals (CIs) of the two treatment regimens were analyzed. RESULTS: This study analyzed 11 articles from the literature with a total of 1,053 subjects. The combination of atropine and omeprazole significantly improved the clinical outcomes of patients with acute gastritis compared to patients treated with combined anisodamine and omeprazole (control group). The effective rate of combined atropine and omeprazole treatment was 1.21 times higher than that observed with the control group, and the incidence of adverse reactions was 0.41 times that of the control group. Atropine combined with omeprazole significantly alleviated the clinical symptoms of the patients. The total treatment time was shortened by 0.57 days, duration of abdominal pain was shortened by 2.82 days, duration of diarrhea was reduced by 1.99 days, and the duration of nausea and vomiting was shortened by 2.68 days compared to the control group. DISCUSSION: The combination of atropine with omeprazole in the treatment of acute gastritis demonstrated a high effective rate with few adverse reactions than. It was effective at alleviating the clinical symptoms associated with acute gastritis. The results of this study provide support for the clinical implementation of combined atropine and omeprazole in the treatment of patients with acute gastritis.

Resolving Cross-Sensitivity Effect in Fluorescence Quenching for Simultaneously Sensing Oxygen and Ammonia Concentrations by an Optical Dual Gas Sensor.

Simultaneous sensing of multiple gases by a single fluorescent-based gas sensor is of utmost importance for practical applications. Such sensing is strongly hindered by cross-sensitivity effects. In this study, we propose a novel analysis method to ameliorate such hindrance. The trial sensor used here was fabricated by coating platinum(II) meso-tetrakis(pentafluorophenyl)porphyrin (PtTFPP) and eosin-Y dye molecules on both sides of a filter paper for sensing O2 and NH3 gases simultaneously. The fluorescent peak intensities of the dyes can be quenched by the analytes and this phenomenon is used to identify the gas concentrations. Ideally, each dye is only sensitive to one gas species. However, the fluorescent peak related to O2 sensing is also quenched by NH3 and vice versa. Such cross-sensitivity strongly hinders gas concentration detection. Therefore, we have studied this cross-sensitivity effect systematically and thus proposed a new analysis method for accurate estimation of gas concentration. Comparing with a traditional method (neglecting cross-sensitivity), this analysis improves O2-detection error from -11.4% ± 34.3% to 2.0% ± 10.2% in a mixed background of NH3 and N2.

Multifunctional nanoparticles for targeting the tumor microenvironment to improve synergistic drug combinations and cancer treatment effects.

Docetaxel-based chemotherapy for prostate cancer is the clinical standard of care. However, nonspecific targeting, multiple drug resistance, and adverse side effects are common obstacles. Various natural compounds, including epigallocatechin-3-gallate (EGCG) in combination with taxane, have the potential to be developed as anticancer therapeutics. Although synergistic hydrophobic-hydrophilic combination drugs have been used with some success, the main drawbacks of this approach are poor bioavailability, unfavorable pharmacokinetics, and low tissue distribution. To improve their synergistic effect and overcome limitations, we encapsulated EGCG and low-dose docetaxel within TPGS-conjugated hyaluronic acid and fucoidan-based nanoparticles. This approach might facilitate simultaneous target-specific markers at the edge and center of the tumor and then might increase intratumoral drug accumulation. Additionally, the successful release of bioactive combination drugs was regulated by the pH-sensitive nanoparticles and internalization into prostate cancer cells through CD44 and P-selectin ligand recognition, and the inhibition of cell growth via induced G2/M phase cell cycle arrest was observed in in vitro study. In in vivo studies, treatment with cancer-targeted combination drug-loaded nanoparticles significantly attenuated tumor growth and increased M30 protein expression without causing organ damage. Overall, the multifunctional nanoparticle system improved the drugs' synergistic effect, indicating great potential in its development as a prostate cancer treatment.

Association of sleep duration with risk of all-cause mortality and poor quality of dying in oldest-old people: a community-based longitudinal study.

BACKGROUND: While sleep duration has been shown to be associated with health outcomes, few studies have been conducted among the oldest old. In addition, the impact of sleep duration on quality of dying is unknown. We aimed to evaluate how sleep duration affects all-cause mortality and quality of dying in people aged 80 + . METHODS: This community-based longitudinal study was performed by using data from 15,048 individuals aged ≥80 with information on sleep duration in the Chinese Longitudinal Healthy Longevity Survey. Cox and logistic regression models with penalized splines were applied to explore the shape of the association between sleep duration and all-cause mortality and poor quality of dying respectively and identify the interval of sleep duration resulting in the lowest risk of both. RESULTS: During a median follow-up of 3.1 years, 11,582 deaths including 4116 individuals who experienced poor quality of dying were recorded. Sleep duration showed a U-shaped association with all-cause mortality and sleeping about 8 h had the minimum risk of death; a J-shaped association was found between sleep duration and poor quality of dying. Compared with sleep duration of 7-9 h, the adjusted hazard ratio of total deaths was 1.08 (95% CI 1.03-1.13) for short duration (< 7 h) and 1.12 (95% CI 1.07-1.17) for long duration (> 9 h); the adjusted odds ratio of poor QOD was 1.10 (95% CI 1.01-1.21) for long duration, but this association was restricted to those with baseline unhealthy status (P-interaction = 0.04). CONCLUSIONS: Sleeping a little longer may be better for individuals over 80 years old, and sleep duration of 7-9 h per day is optimal for both survival and good quality of life near death.

The association of healthy behaviors with cognitive health expectancy in Chinese older adults: a population-based cohort study.

OBJECTIVE: To examine how lifestyles and leisure activities are associated with cognitive health expectancy among older adults. RESULTS: For young-old (aged 65), an absolute increase in life years without cognitive impairment was found among those with a healthy diet, engaging in mental activities and in social activities. For old-old (aged 85), an absolute increase was found for men engaging in physical activities besides those. Compared with counterparts in a high risk group, the young-old in a medium-low risk group had a smaller proportion of years without cognitive impairment. Old-old in a low risk group had a greater proportion. CONCLUSION: Extra years of life gained by a healthy dietary pattern, mental activities, and social activities are free of cognitive impairment for both sexes across ages. The beneficial impact of individual and combined modifiable factors on cognitive health is most prominent in old-old. METHODS: Data come from The Chinese Longitudinal Healthy Longevity Survey, a population-based cohort study of 27,193 participants aged 65+ conducted between 2002 and 2014. Smoking status, alcohol consumption, dietary pattern, marital status, physical, mental, social, and productive activities were assessed at baseline. Cognitive status was measured using the Chinese version of the MMSE.

Loss of CPAP in developing mouse brain and its functional implication for human primary microcephaly.

Primary microcephaly (MCPH) is a neurodevelopmental disorder characterized by small brain size with mental retardation. CPAP (also known as CENPJ), a known microcephaly-associated gene, plays a key role in centriole biogenesis. Here, we generated a previously unreported conditional knockout allele in the mouse Cpap gene. Our results showed that conditional Cpap deletion in the central nervous system preferentially induces formation of monopolar spindles in radial glia progenitors (RGPs) at around embryonic day 14.5 and causes robust apoptosis that severely disrupts embryonic brains. Interestingly, microcephalic brains with reduced apoptosis are detected in conditional Cpap gene-deleted mice that lose only one allele of p53 (also known as Trp53), while simultaneous removal of p53 and Cpap rescues RGP death. Furthermore, Cpap deletion leads to cilia loss, RGP mislocalization, junctional integrity disruption, massive heterotopia and severe cerebellar hypoplasia. Together, these findings indicate that complete CPAP loss leads to severe and complex phenotypes in developing mouse brain, and provide new insights into the causes of MCPH.

pH sensitive peptide functionalized nanoparticles for co-delivery of erlotinib and DAPT to restrict the progress of triple negative breast cancer.

Although a variety of drug delivery strategies have been designed for enhancing the treatment of Triple negative breast cancer (TNBC), combating with TNBCs is still dramatically challenged by the selection of appropriate therapeutic targets and insufficient tumor accumulation or inner penetration of chemotherapeutics. To address these issues, the classical EGFR-inhibitor, erlotinib (EB), was selected as the model drug here and PLA-based nano-platform (NP-EB) was prepared for tumor site drug delivery. Given the significant role of Notch-EGFR interplay in raising severe resistance to EGFR inhibition of EB, gamma secretase inhibitor (GSI)-DAPT was further entrapped into the core of nanoparticles to inhibit the activation of Notch signaling (NP-EB/DART). For achieving the goal of tumor targeting drug delivery, we developed a new peptide CF and decorating it on the surface of EB/DART-dual loaded nanoparticles (CF-NP-EB/DART). Such CF peptide was designed by conjugating two separated peptide CREKA, tumor-homing peptide, and F3, cell penetrating peptide, to together via a pH-sensitive hydrazone bond. By this way, the tumor unspecific property of F3 was sealed and significantly reduced the site effects. However, after the nanoparticles reach the tumor site, the pH-sensitive linkage can be broken down by the unique acidic environment of tumor, and subsequently discovered the F3 peptide to penetrate into tumor cells.

Cognitive functioning transitions, health expectancies, and inequalities among elderly people in China: A nationwide longitudinal study.

OBJECTIVE: In China, cognitive impairment has become a huge challenge owing to the rapid aging process. We investigate cognitive health expectancy and potential factors leading to inequalities of cognitive health for Chinese older people. METHODS: The study included 19 943 participants aged 65 to 95 at the first observation in Chinese Longitudinal Healthy Longevity Survey collected during 2002-2014. Cognitive impairment was categorized into none, mild, and severe by the score of cMMSE. Multistate models based on continuous-time Markov process were applied to calculate cognitive health expectancies and estimate hazard ratio from no impairment to impairment for potential factors. RESULTS: Urban women and men aged 65 were expected to spend 31.18% and 19.82% of their remaining 17.46 and 15.45 years with cognitive impairment; meanwhile, rural women and men aged 65 were expected to spend 35.31% and 21.39% of their remaining 16.73 and 14.87 years with cognitive impairment. Women achieving lower educational attainment (HR1-6 years  = 0.78, 95% CI, 0.71-0.87; HR7+ years  = 0.59, 95% CI, 0.49-0.70) than men and rural residents having less access to medical service (HR = 0.79, 95% CI, 0.68-0.92) and doing less regular exercise (HR = 0.87, 95% CI, 0.80-0.96) than urban people caused the differences of cognitive health for genders and regions. CONCLUSIONS: Women and rural people experience less cognitive health expectancies compared with their counterparts, respectively. Chinese government should pay more attention to rural women and make efforts to reduce the inequalities of cognitive health by increasing opportunities of education for women and improving access to medical service and healthy lifestyle for rural people.

A 3D intestinal tissue model supports Clostridioides difficile germination, colonization, toxin production and epithelial damage.

Endospore-forming Clostridioides difficile is a causative agent of antibiotic-induced diarrhea, a major nosocomial infection. Studies of its interactions with mammalian tissues have been hampered by the fact that C. difficile requires anaerobic conditions to survive after spore germination. We recently developed a bioengineered 3D human intestinal tissue model and found that low O2 conditions are produced in the lumen of these tissues. Here, we compared the ability of C. difficile spores to germinate, produce toxin and cause tissue damage in our bioengineered 3D tissue model versus in a 2D transwell model in which human cells form a polarized monolayer. 3D tissue models or 2D polarized monolayers on transwell filters were challenged with the non-toxin producing C. difficile CCUG 37787 serotype X (ATCC 43603) and the toxin producing UK1 C. difficile spores in the presence of the germinant, taurocholate. Spores germinated in both the 3D tissue model as well as the 2D transwell system, however toxin activity was significantly higher in the 3D tissue models compared to the 2D transwells. Moreover, the epithelium damage in the 3D tissue model was significantly more severe than in 2D transwells and damage correlated significantly with the level of toxin activity detected but not with the amount of germinated spores. Combined, these results show that the bioengineered 3D tissue model provides a powerful system with which to study early events leading to toxin production and tissue damage of C. difficile with mammalian cells under anaerobic conditions. Furthermore, these systems may be useful for examining the effects of microbiota, novel drugs and other potential therapeutics directed towards C. difficile infections.

Multifunctional Bioreactor System for Human Intestine Tissues.

The three-dimensional (3D) cultivation of intestinal cells and tissues in dynamic bioreactor systems to represent in vivo intestinal microenvironments is essential for developing regenerative medicine treatments for intestinal diseases. We have previously developed in vitro human intestinal tissue systems using a 3D porous silk scaffold system with intestinal architectures and topographical features for the adhesion, growth, and differentiation of intestinal cells under static culture conditions. In this study, we designed and fabricated a multifunctional bioreactor system that incorporates pre-epithelialized 3D silk scaffolds in a dynamic culture environment for in vitro engineering of human intestine tissues. The bioreactor system allows for control of oxygen levels in perfusion fluids (aerobic simulated intestinal fluid (SIF), microaerobic SIF, and anaerobic SIF), while ensuring control over the mechanical and chemical microenvironments present in native human intestines. The bioreactor system also enables 3D cell culture with spatial separation and cultivation of cocultured epithelial and stromal cells. Preliminary functional analysis of tissues housed in the bioreactor demonstrated that the 3D tissue constructs survived and maintained typical phenotypes of intestinal epithelium, including epithelial tight junction formation, intestinal biomarker expression, microvilli formation, and mucus secretion. The unique combination of a dynamic bioreactor and 3D intestinal constructs offers utility for engineering human intestinal tissues for the study of intestinal diseases and discovery options for new treatments.

Human microcephaly protein RTTN interacts with STIL and is required to build full-length centrioles.

Mutations in many centriolar protein-encoding genes cause primary microcephaly. Using super-resolution and electron microscopy, we find that the human microcephaly protein, RTTN, is recruited to the proximal end of the procentriole at early S phase, and is located at the inner luminal walls of centrioles. Further studies demonstrate that RTTN directly interacts with STIL and acts downstream of STIL-mediated centriole assembly. CRISPR/Cas9-mediated RTTN gene knockout in p53-deficient cells induce amplification of primitive procentriole bodies that lack the distal-half centriolar proteins, POC5 and POC1B. Additional analyses show that RTTN serves as an upstream effector of CEP295, which mediates the loading of POC1B and POC5 to the distal-half centrioles. Interestingly, the naturally occurring microcephaly-associated mutant, RTTN (A578P), shows a low affinity for STIL binding and blocks centriole assembly. These findings reveal that RTTN contributes to building full-length centrioles and illuminate the molecular mechanism through which the RTTN (A578P) mutation causes primary microcephaly.Mutations in many centriolar protein-encoding genes cause primary microcephaly. Here the authors show that human microcephaly protein RTTN directly interacts with STIL and acts downstream of STIL-mediated centriole assembly, contributing to building full-length centrioles.

Novel Bioengineered Three-Dimensional Human Intestinal Model for Long-Term Infection of Cryptosporidium parvum.

Cryptosporidium spp. are apicomplexan parasites of global importance that cause human diarrheal disease. In vitro culture models that may be used to study this parasite and that have physiological relevance to in vivo infection remain suboptimal. Thus, the pathogenesis of cryptosporidiosis remains poorly characterized, and interventions for the disease are limited. In this study, we evaluated the potential of a novel bioengineered three-dimensional (3D) human intestinal tissue model (which we developed previously) to support long-term infection by Cryptosporidium parvum Infection was assessed by immunofluorescence assays and confocal and scanning electron microscopy and quantified by quantitative reverse transcription-PCR. We found that C. parvum infected and developed in this tissue model for at least 17 days, the extent of the study time used in the present study. Contents from infected scaffolds could be transferred to fresh scaffolds to establish new infections for at least three rounds. Asexual and sexual stages and the formation of new oocysts were observed during the course of infection. Additionally, we observed ablation, blunting, or distortion of microvilli in infected epithelial cells. Ultimately, a 3D model system capable of supporting continuous Cryptosporidium infection will be a useful tool for the study of host-parasite interactions, identification of putative drug targets, screening of potential interventions, and propagation of genetically modified parasites.

Electrochemically Directed Assembly of Designer Coiled-Coil Telechelic Proteins.

We report the design and characterization of a de novo electrogelation protein comprising a central spider silk glue motif flanked by terminal pH-triggered coiled-coil domains. The coiled-coiled domains were designed to form intramolecular helix bundles below a sharply defined pH-trigger point (∼pH 5.3), whereas the spider silk glue protein, because of its substantial Glu content, serves both as an anionic electrophoretic transport element at neutral and elevated pH and as a disordered linker chain between the associated helix bundles at reduced pH. We show that in an electrochemical cell, a solution of these telechelic proteins migrates toward the anode where the terminal coiled-coil domains are triggered to form coiled-coil assemblies that act as transient cross-links for the e-gel state. Upon cessation of the current, the coiled-coil domains become denatured and the e-gel transforms back into a fluid solution of polypeptides in a fully reversible manner. This simplified triblock protein design mimics many of the characteristics of more complex electrogelation proteins, such as silk fibroin. As such, it provides some insight into possible general mechanisms of protein electrogelation. Moreover, this general class of electrogelation proteins has the potential for biomedical applications of electrochemically triggered gelation, such as externally switchable delivery of therapeutic cell and drugs from a responsive matrix.