Sleeve gastrectomy links the attenuation of diabetic kidney disease to the inhibition of renal tubular ferroptosis through down-regulating TGF-β1/Smad3 signaling pathway

PURPOSE

To investigate how sleeve gastrectomy (SG), a typical operation of bariatric surgery, attenuated symptom, and progression of diabetic kidney disease (DKD).

METHODS

DKD model was induced by high-fat diet (HFD) combined with streptozocin in Wistar rats. SG was performed, and the group subjected to sham surgery served as control. The animals were euthanized 12 weeks after surgery, followed by sample collection for the subsequent experiment. The HK-2, a renal proximal tubular epithelial cell line derived from human, was utilized to investigate the potential mechanisms.

RESULTS

SG improved metabolic parameters and glucose homeostasis, and could alleviate DKD in terms of renal function indices as well as histological and morphological structures in DM rats, accompanied with a significant reduction in renal tubular injury. Compared with sham group, SG reduced the renal tubular ferroptosis. To further clarify the mechanism involved, in vitro experiments were performed. In the presence of high glucose, renal tubular TGF-β1 secretion was significantly increased in HK-2 cell line, which led to activation of ferroptosis through TGF-β1/Smad3 signaling pathway. Inhibition of TGF-β1 receptor and phosphorylation of Smad3 significantly ameliorated TGF-β1-mediated ferroptosis. In vivo experiments also found that SG improved the hyperglycemic environment, reduced renal TGF-β1 concentrations, and down-regulated the TGF-β1/Smad3 signaling pathway.

CONCLUSIONS

With the capacity to lower the glucose, SG could attenuate the ferroptosis by inhibiting TGF-β1/Smad3 signaling pathway in DKD rats, and eventually attenuated DKD.

[Effect of ground cage use on Oncomelania hupensis spread]

OBJECTIVE

To examine the effect of ground cage use on Oncomelania hupensis spread, so as to provide insights into precision snail control.

METHODS

Twenty ground cages that were frequently used to capture rice field eels were purchased, including 11 packaging tape-made cages, 7 plastic cages and 2 nylon rope-made cages. The eel-capturing activity was mimicked, and 20 ground cages were assigned in settings with relatively high (1.00 snail/0.1 m2 and higher) and low snail densities (< 1.00 snail/0.1 m2) in Xindai Township, Pinghu City, Zhejiang Province during the period from 15 : 00 to 8 : 00 of the following day on April 13, 26 and 28. The numbers of snails carried by different types of ground cages were compared in settings with different types of snail densities using the rank-sum test.

RESULTS

A total of 11 cage-times were assigned in settings with a high snail density, and a total of 77 snails were captured, with a mean number of 7 snails in each cage-time and 2.15 snails in 0.1 m2 ground cage. The mean numbers of snails carried by packaging tape-made and plastic cages were 2.47 snails/0.1 m2 cage and 0.37 snails/0.1 m2 cage, respectively. A total of 24 cage-times were assigned in settings with a low snail density, and a total of 8 snails were captured, with a mean number of 0.33 snails in each cage-time and 0.09 snails in 0.1 m2 ground cage. The mean numbers of snails carried by packaging tape-made cages were 0.12 snails/0.1 m2 cage; however, no snails were carried by plastic or nylon rope-made cages. The number of snails carried by ground cages was higher in settings with a high snail density than in settings with a low snail density (Z = -4.019, P < 0.01), and the number of snails carried by packaging tape-made cages was higher in settings with a high snail density than in settings with a low snail density (Z = -4.086, P < 0.01). No significant differences were found in the numbers of snails carried by different types of ground cages.

CONCLUSIONS

The use of ground cage in snail habitats is a contributor to snail spread.

AAV9-based PMM2 gene replacement augments PMM2 expression and improves glycosylation in primary fibroblasts of patients with phosphomannomutase 2 deficiency (PMM2-CDG)

Inherited deficiency of phosphomannomutase 2 (PMM2) (aka PMM2-CDG) is the most common congenital disorders of glycosylation (CDG) and has no cure. With debilitating morbidity and significant mortality, it is imperative to explore novel, safe, and effective therapies for the disease. Our Proof-of-Concept study showed that AAV9-PMM2 infection of patient fibroblasts augmented PMM2 expression and improved glycosylation. Thus, AAV9-PMM2 gene replacement is a promising therapeutic strategy for PMM2-CDG patients.

Noninvasive Radiation Markers Based on Lung Cancer CT Images and Dosimetry Features to Predict the Immune Response to Radiotherapy in Tumor Microenvironment

PURPOSE/OBJECTIVE(S)

For lung cancer patients with complex conditions, doctors need to determine treatment plan in combination with changes of immune response during radiotherapy. It was urgent to find a strategy to predict immune response to intervene the treatment at an early stage.

MATERIALS/METHODS

The radiotherapy process and tumor microenvironment status of 105 lung cancer patients were tracked and recorded in our hospital from 2019 to 2022, public database TCGA-LUAD/LUSC queue of TCIA image data was downloaded as external verification set. Data was analyzed according to the following methods: First, the 3D slicer software was used to process the CT imageomics data, and the doseomics information was calculated by DVHmetrics package from R software. Then Python was brought in to develop a non-invasive radiation scoring system through machine learning methods (T-test, LASSO, random forest and Xgboost). Finally, combined with the clinical information related to the patient's immune response, a nomogram was made to study the correlation between the score markers and the ratio of CD4 cells/CD8 cells in the tumor microenvironment, the prognosis of lung cancer, as well as the incidence of radiation pneumonia.

RESULTS

The radiation markers score formula was obtained with CT imageomics and DVH dosimics features, which achieved an AUC of 0.67-0.75 in predicting CD4/CD8 condition in tumor microenvironment after radiotherapy. It was worth noticing that in predicting the prognosis of lung cancer, it was difficult to distinguish between the radiation score and the patient's survival status (P>0.05). However, we found that the radiation pneumonitis of lung cancer patients in the low score group (42.6%) was significantly higher than that in the high score group (13.4%).

CONCLUSION

Radiation markers score was a non-invasive method to evaluate the immune response of patients with lung cancer, which can be used to predict the incidence of radiation pneumonitis.

First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment

We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03)  ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3)  events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47}  cm^{2} for a WIMP mass of 28  GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.

"Double-edged sword" effect of reactive oxygen species (ROS) in tumor development and carcinogenesis

Reactive oxygen species (ROS) are small reactive molecules produced by cellular metabolism and regulate various physiological and pathological functions. Many studies have shown that ROS plays an essential role in the proliferation and inhibition of tumor cells. Different concentrations of ROS can have a "double-edged sword" effect on the occurrence and development of tumors. A certain concentration of ROS can activate growth-promoting signals, enhance the proliferation and invasion of tumor cells, and cause damage to biomacromolecules such as proteins and nucleic acids. However, ROS can enhance the body's antitumor signal at higher levels by initiating oxidative stress-induced apoptosis and autophagy in tumor cells. This review analyzes ROS's unique bidirectional regulation mechanism on tumor cells, focusing on the key signaling pathways and regulatory factors that ROS affect the occurrence and development of tumors and providing ideas for an in-depth understanding of the mechanism of ROS action and its clinical application.

Searching for Heavy Dark Matter near the Planck Mass with XENON1T

Multiple viable theoretical models predict heavy dark matter particles with a mass close to the Planck mass, a range relatively unexplored by current experimental measurements. We use 219.4 days of data collected with the XENON1T experiment to conduct a blind search for signals from multiply interacting massive particles (MIMPs). Their unique track signature allows a targeted analysis with only 0.05 expected background events from muons. Following unblinding, we observe no signal candidate events. This Letter places strong constraints on spin-independent interactions of dark matter particles with a mass between 1×10^{12} and 2×10^{17}  GeV/c^{2}. In addition, we present the first exclusion limits on spin-dependent MIMP-neutron and MIMP-proton cross sections for dark matter particles with masses close to the Planck scale.

Dopamine-independent development and maintenance of mouse striatal medium spiny neuron dendritic spines

Striatal medium spiny neurons (MSNs) and striatal dopamine (DA) innervation are profoundly important for brain function such as motor control and cognition. A widely accepted theory posits that striatal DA loss causes (or leads to) MSN dendritic atrophy. However, examination of the literature indicates that the data from Parkinson's disease (PD) patients and animal PD models were contradictory among studies and hard to interpret. Here we have re-examined the potential effects of DA activity on MSN morphology or lack thereof. We found that in 15-day, 4- and 12-month old Pitx3 null mutant mice that have severe DA denervation in the dorsal striatum while having substantial residual DA innervation in the ventral striatum, MSN dendrites and spine numbers were similar in dorsal and ventral striatum, and also similar to those in normal mice. In 15-day, 4- and 12-month old tyrosine hydroxylase knockout mice that cannot synthesize L-dopa and thus have no endogenous DA in the entire brain, MSN dendrites and spine numbers were also indistinguishable from age-matched wild-type (WT) mice. Furthermore, in adult WT mice, unilateral 6-OHDA lesion at 12 months of age caused an almost complete striatal DA denervation in the lesioned side, but MSN dendrites and spine numbers were similar in the lesioned and control sides. Taken together, our data indicate that in mice, the development and maintenance of MSN dendrites and spines are DA-independent such that DA depletion does not trigger MSN dendritic atrophy; our data also suggest that the reported MSN dendritic atrophy in PD may be a component of neurodegeneration in PD rather than a consequence of DA denervation.

Secreted endogenous macrosomes reduce Aβ burden and ameliorate Alzheimer's disease

Innovative therapeutic strategies are urgently needed for Alzheimer's disease (AD) due to the increasing size of the aging population and the lack of effective drug treatment. Here, we report the therapeutic effects of extracellular vesicles (EVs) secreted by microglia, including macrosomes and small EVs, on AD-associated pathology. Macrosomes strongly inhibited β-amyloid (Aβ) aggregation and rescued cells from Aβ misfolding-induced cytotoxicity. Furthermore, macrosome administration reduced Aβ plaques and ameliorated cognitive impairment in mice with AD. In contrast, small EVs slightly promoted Aβ aggregation and did not improve AD pathology. Proteomic analysis of small EVs and macrosomes revealed that macrosomes harbor several important neuroprotective proteins that inhibit Aβ misfolding. In particular, the small integral membrane protein 10-like protein 2B in macrosomes has been shown to inhibit Aβ aggregation. Our observations provide an alternative therapeutic strategy for the treatment of AD over conventional ineffective drug treatments.

[Efficacy of video-assisted thoracoscopic surgical decortication for stage Ⅲ tuberculous empyema]

Objective: To investigate the clinical efficacy, safety and feasibility of "double-portal" video-assisted thoracoscopic surgical(VATS) decortication among patients with stage Ⅲ tuberculous empyema, and then to evaluate the recovery of chest deformity. Method: This study was a single center retrospective study. A total of 49 patients with stage Ⅲ tuberculous empyema who underwent VATS pleural decortication at the Department of Thoracic Surgery, Public Health Clinical Center of Chengdu between June 2017 and April 2021 were enrolled, including 38 males, and 11 females, aged 13-60 (27.5±10.4) years. The safety and feasibility of VATS were further evaluated. The inner circumference of the chest on sternal and xiphoid planes on chest CT scans before and 1, 3, 6, 12months after decortication were collected through the measuring software of the CT. The samples in-pair test was used to compare the changes in the chest to reflect the recovery of the chest deformity. Results: In the 49 patients, The surgical time was (186±61) min, and the volume of blood loss was (366±267) ml. There were 8 cases (16.33%) with postoperative complications during the perioperative period. Constant air leak and pneumonia were the main postoperative complications. No relapse of empyema or dissemination of tuberculosis occured during the period of follow-up. Before surgery, the inner thoracic circumference of the thorax at the level of the carina plane was (655±54) mm, and the inner thoracic circumference of the thorax at the level of the xiphoid plane was (720±69) mm. Patients were followed for 12-36 months. The inner thoracic circumference of the thoracic cavity at the level of carina was (666±51), (667±47) and (671±47) mm at the 3rd, 6th and 12th months after operation, which were significantly larger than that at the level of carina before operation (all P<0.05). The inner thoracic circumference diameter of the thoracic cavity measured at the xiphoid level at the 3rd, 6th and 12th months after the operation was (730±65), (733±63) and (735±63) mm respectively(all P<0.05).The inner thoracic circumference of the thoracic cavity increased significantly than that before surgery (P<0.05). At 6 months after operation, there was significant difference in the improvement of the inner thoracic circumference of the carina plane in patients with age less than 20 years and FEV₁% less than 80% (P=0.015, P=0.003). The improvement in the inner thoracic circumference of the carina plane in patients with pleural thickening≥8 mm compared with those with less than 8 mm was not statistically different(P=0.070). Conclusions: For some patients with stage Ⅲ tuberculous empyema, pleural decortication under thoracoscopy is safe and feasible, and can significantly restore the inner thoracic circumference of the patient's chest, improve the collapse of the patient's chest, and have significant clinical effect. The "double-portal VATS" surgical technology has the advantage of less trauma, wide operation field, large operation space and is easy to master, which is worth further exploring for clinical application.

An interpretable machine learning model for real-time sepsis prediction based on basic physiological indicators

OBJECTIVE

In view of the important role of risk prediction models in the clinical diagnosis and treatment of sepsis, and the limitations of existing models in terms of timeliness and interpretability, we intend to develop a real-time prediction model of sepsis with high timeliness and clinical interpretability.

PATIENTS AND METHODS

We used eight real-time basic physiological monitoring indicators of patients, including heart rate, respiratory rate, oxygen saturation, mean arterial pressure, systolic blood pressure, diastolic blood pressure, temperature and blood glucose, extracted three-hour dynamic feature sequences, and calculated 3 linear parameters (mean, standard deviation, and endpoint value), a 24-dimensional feature vector was constructed, and finally a real-time sepsis prediction model was constructed based on the Local Interpretable Model-Agnostic Explanation (LIME) interpretability method.

RESULTS

The area under the receiver operating characteristic curve (AUROC), Accuracy and F1 scores of Extremely Randomized Trees we built were higher than those of other models, with AUROC above 0.76, showing the best performance. The Imbalance XGBoost has a high specificity (0.86) in predicting sepsis. The LIME local interpretable model we built can display a large amount of valid model prediction details for clinical workers' reference, including the prediction probability and the influence of each feature on the prediction result, thus effectively assisting the work of clinical workers and improving diagnostic efficiency.

CONCLUSIONS

This model can provide real-time dynamic early warning of sepsis for critically ill patients under supervision and provide a reference for clinical decision support. At the same time, interpretive analysis of sepsis prediction models can improve the credibility of the models.

[Uterine POLE mutant endometrioid carcinoma combined with human papilloma virus-associated cervical adenocarcinoma: A case report and literature review]

Independent primary uterine and cervical adenocarcinoma are rare and difficult to identify their origins, which makes treatment decision difficult. A 46-year-old female with endometrioid carcinoma and adenocarcinoma, human papilloma virus (HPV)-associated of the uterine cervix was reported. The patient presented with increased menstrual flow, contact bleeding and watery leucorrhea for more than one year, and the imaging findings showed abnormal uterine morphology, irregular margins, and multiple abnormal signals in uterine cavity and myometrium, which suggested multiple leiomyomas of the uterus. The signal intensity in the right muscle layer was markedly enhanced, suggesting a smooth muscle tumor of uncertain malignant potential. A large number of cystic hypointensity was seen in the cervix, and multiple cysts were considered. The initial preoperative diagnosis was multiple leiomyoma of the uterus, and a hysterectomy operation was planned. During the operation, the uterus was sent for frozen sections. There was a mass in the endometrium of the fundus, with a soft grayish-red cut surface and a clear border with the myometrium, and there was a grayish-white nodule in the cervix with a hard grayish-white cut surface. The two masses were well demarcated from each other, and the distance between them was 30 mm. The result of the frozen sections indicated the malignant tumor of the endometrium, and the extended hysterectomy+pelvic lymphadenectomy+partial resection of the greater omentum was performed. After the operation, the paraffin sections were sent to the Department of Pathology of the Peking University Third Hospital for histochemistry, POLE gene sequencing and HPV RNAscope tests, and the final diagnosis was a synchronous endometrioid carcinoma (POLE-mutant according to the WHO classification) and an adenocarcinoma, HPV-associated of the uterine cervix. Now the patient had been treated with 2 cycles of chemotherapy and her condition was fine. Through the analysis of the histological, immunohistochemical and molecular detection results of this case, the importance of applying HPV RNAscope and TCGA molecular typing in the diagnosis of cervical adenocarcinomas and endometrial carcinomas was emphasized. At the same time, gynecologists should not blindly rely on intraoperative frozen sections, and should pay attention to preoperative pathological examination, and make appropriate operation methods according to the results in order to prevent passivity in the surgery.

Search for New Physics in Electronic Recoil Data from XENONnT

We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target reduced the background in the (1, 30) keV search region to (15.8±1.3)  events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.

[Bedside monitoring of lung perfusion by electrical impedance tomography]

As a non-invasive and radiation-free bedside imaging method, electrical impedance tomography (EIT) can perform real-time regional pulmonary ventilation evaluation and pulmonary blood flow monitoring for patients, thus realizing bedside ventilation/perfusion matching visualization, effectively guiding the pathophysiological mechanism of hypoxemia, and providing a new method for the study of pulmonary blood flow. EIT has also played a unique and irreplaceable role in COVID-19 research and treatment. At the same time, as functional imaging, the operation details and image reconstruction algorithm of this technology still need to be further optimized by more researches to provide a more robust evaluation in clinical application. In this paper, EIT pulmonary blood flow monitoring methods, operation and implementation of monitoring indicators, application and related research progress will be described.

ATP13A2 Declines Zinc-Induced Accumulation of α-Synuclein in a Parkinson’s Disease Model

Parkinson’s disease (PD) is characterized by the presence of Lewy bodies caused by α-synuclein. The imbalance of zinc homeostasis is a major cause of PD, promoting α-synuclein accumulation. ATP13A2, a transporter found in acidic vesicles, plays an important role in Zn²⁺ homeostasis and is highly expressed in Lewy bodies in PD-surviving neurons. ATP13A2 is involved in the transport of zinc ions in lysosomes and exosomes and inhibits the aggregation of α-synuclein. However, the potential mechanism underlying the regulation of zinc homeostasis and α-synuclein accumulation by ATP13A2 remains unexplored. We used α-synuclein-GFP transgenic mice and HEK293 α-synuclein-DsRed cell line as models. The spatial exploration behavior of mice was significantly reduced, and phosphorylation levels of α-synuclein increased upon high Zn²⁺ treatment. High Zn²⁺ also inhibited the autophagy pathway by reducing LAMP2a levels and changing the expression of LC3 and P62, by reducing mitochondrial membrane potential and increasing the expression of cytochrom C, and by activating the ERK/P38 apoptosis signaling pathway, ultimately leading to increased caspase 3 levels. These protein changes were reversed after ATP13A2 overexpression, whereas ATP13A2 knockout exacerbated α-synuclein phosphorylation levels. These results suggest that ATP13A2 may have a protective effect on Zn²⁺-induced abnormal aggregation of α-synuclein, lysosomal dysfunction, and apoptosis.

Material radiopurity control in the XENONnT experiment

The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim $$\end{document}∼17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn activity concentration in XENONnT is determined to be 4.2 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{+0.5}_{-0.7}$$\end{document}-0.7+0.5) \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu $$\end{document}μBq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.

Aspartic Acid-Modified Phospholipids Regulate Cell Response and Rescue Memory Deficits in APP/PS1 Transgenic Mice

Misfolding and accumulation of amyloid-β (Aβ) to form senile plaques are the main neuropathological signatures of Alzheimer's disease (AD). Decreasing Aβ production, inhibiting Aβ aggregation, and clearing Aβ plaques are thus considered an important strategy for AD treatment. However, numerous drugs cannot enter the AD clinical trials due to unsatisfactory biocompatibility, poor blood-brain barrier penetration, little biomarker impact, and/or low therapeutic indicators. Here, a pair of chiral aspartic acid-modified 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (l- and d-Asp-DPPE) are prepared to build stabilized chiral liposomes. We find that both l- and d-liposomes are able to rescue Aβ aggregation-induced apoptosis, oxidative stress, and calcium homeostasis, in which the effect of d-liposomes is more obvious than that of l-ones. Furthermore, in AD model mice (APPswe/PS1d9 double-transgenic mice), chiral liposomes not only show biosafety but also strongly improve cognitive deficits and reduce Aβ deposition in the brain. Our results suggest that chiral liposomes, particularly, d-liposomes, could be a potential therapeutic approach for AD treatment. This study opens new horizons by showing that liposomes will be used for drug development in addition to delivery and targeting functions.

Juliana JR, Stovall DB, Whittington R, Zhong M, Ballen CJ. Context Matters: Social Psychological Factors That Underlie Academic Performance across Seven Institutions

To enhance equity and diversity in undergraduate biology, recent research in biology education focuses on best practices that reduce learning barriers for all students and improve academic performance. However, the majority of current research into student experiences in introductory biology takes place at large, predominantly White institutions. To foster contextual knowledge in biology education research, we harnessed data from a large research coordination network to examine the extent of academic performance gaps based on demographic status across institutional contexts and how two psychological factors, test anxiety and ethnicity stigma consciousness, may mediate performance in introductory biology. We used data from seven institutions across three institution types: 2-year community colleges, 4-year inclusive institutions (based on admissions selectivity; hereafter, inclusive), and 4-year selective institutions (hereafter, selective). In our sample, we did not observe binary gender gaps across institutional contexts, but found that performance gaps based on underrepresented minority status were evident at inclusive and selective 4-year institutions, but not at community colleges. Differences in social psychological factors and their impacts on academic performance varied substantially across institutional contexts. Our findings demonstrate that institutional context can play an important role in the mechanisms underlying performance gaps.

A Novel Cu(II)-Binding Peptide Identified by Phage Display Inhibits Cu2+-Mediated Aβ Aggregation

Copper (Cu) has been implicated in the progression of Alzheimer’s disease (AD), and aggregation of Cu and amyloid β peptide (Aβ) are considered key pathological features of AD. Metal chelators are considered to be potential therapeutic agents for AD because of their capacity to reduce metal ion-induced Aβ aggregation through the regulation of metal ion distribution. Here, we used phage display technology to screen, synthesize, and evaluate a novel Cu(II)-binding peptide that specifically blocked Cu-triggered Aβ aggregation. The Cu(II)-binding peptide (S-A-Q-I-A-P-H, PCu) identified from the phage display heptapeptide library was used to explore the mechanism of PCu inhibition of Cu²⁺-mediated Aβ aggregation and Aβ production. In vitro experiments revealed that PCu directly inhibited Cu²⁺-mediated Aβ aggregation and regulated copper levels to reduce biological toxicity. Furthermore, PCu reduced the production of Aβ by inhibiting Cu²⁺-induced BACE1 expression and improving Cu(II)-mediated cell oxidative damage. Cell culture experiments further demonstrated that PCu had relatively low toxicity. This Cu(II)-binding peptide that we have identified using phage display technology provides a potential therapeutic approach to prevent or treat AD.

Brain Targeting and Aβ Binding Bifunctional Nanoparticles Inhibit Amyloid Protein Aggregation in APP/PS1 Transgenic Mice

Alzheimer's disease (AD) is an insidious and progressive neurodegenerative disease with few disease-modifying treatments. A variety of peptide/protein drugs have neuroprotective effects, which brings new hope for the treatment of AD. However, the application of these drugs is limited because of their low specificity and difficulty in crossing the blood-brain barrier. Herein, using the phage display technology, we identified the Aβ oligomer binding peptide (KH) and the brain targeting peptide (IS). We combined these peptides to develop a bifunctional nanoparticle (IS@NP/KH) for the delivery of Aβ_1-42 oligomer binding peptide into the brain. Intranasal administration of IS@NP/KH significantly attenuated the cognitive and behavioral deficits and reduced the Aβ deposition in the brain of an AD animal model (APPswe/PS 1d9 double-transgenic mice). Our results suggest that intranasal IS@NP/KH administration could be a novel therapeutic strategy for the treatment of AD.