Modulating β-catenin/BCL9 interaction with cell-membrane-camouflaged carnosic acid to inhibit Wnt pathway and enhance tumor immune response

IntroductionLung adenocarcinoma (LUAD) therapies are plagued by insufficient immune infiltration and suboptimal immune responses in patients, which are closely associated with the hyperactive Wnt/β-catenin pathway. Suppressing this signaling holds considerable promise as a potential tumor therapy for LUAD, but Wnt suppressor development is hindered by concerns regarding toxicity and adverse effects due to insufficient targeting of tumors.MethodsWe have synthesized a tumor-specific biomimetic Wnt pathway suppressor, namely CM-CA, by encapsulating carnosic acid within Lewis lung carcinoma (LLC) cell membranes. It possesses nano-size, allowing for a straightforward preparation process, and exhibits the ability to selectively target the Wnt/β-catenin pathway in lung adenocarcinoma cells. To evaluate its in vivo efficacy, we utilized the LLC Lewis homograft model, and further validated its mechanism of action through immunohistochemistry staining and transcriptome sequencing analyses.ResultsThe findings from the animal experiments demonstrated that CM-CA effectively suppressed the Wnt/β-catenin signaling pathway and impeded cellular proliferation, leading to notable tumor growth inhibition in a biologically benign manner. Transcriptome sequencing analyses revealed that CM-CA promoted T cell infiltration and bolstered the immune response within tumor tissues.ConclusionThe utilization of CM-CA presents a novel and auspicious approach to achieve tumor suppression and augment the therapeutic response rate in LUAD, while also offering a strategy for the development of Wnt/β-catenin inhibitors with biosafety profile

Synthetic θ‐Defensin Antibacterial Peptide as a Highly Efficient Nonviral Vector for Redox‐Responsive miRNA Delivery

Synthetic cationic vectors have shown great promise for nonviral gene delivery. However, their cytotoxicity and low efficiency impose great restrictions on clinic applications. To push through this limitation, humanized peptides or proteins with cationic biocompatibility as well as biodegradation would be an excellent candidate. Herein, for the first time, we describe how an arginine‐rich humanized antimicrobial cyclopeptide, θ‐defensin, can be used as a synthetic cationic vector to load and deliver miRNA into bone mesenchymal stem cells with high efficiency and ultralow cytotoxicity, surpassing the efficiency of the commercial polyethylenimine (25 kD) and Lipofectamine 3000. To note, θ‐defensin can redox‐responsively release the loaded miRNA through a structural change: in extracellular oxidative environment, θ‐defensin has large β‐sheet structures stabilized by three disulfide linkages, and this special structure enables highly efficient delivery of miRNA by passing through cell membranes; in intracellular environment, redox‐responsive disulfide linkages are broken and the tight β‐sheet structures are destroyed, so that the miRNA can be released. Our results suggest that synthetic θ‐defensin peptides are a new class of nonviral gene vectors and this study may also provide a promising strategy to design smart‐responsive gene vectors with high efficiency and minimal toxicity.This study describes how an arginine‐rich humanized antimicrobial cyclopeptide, θ‐defensin, can be used as a synthetic cationic vector to load and deliver miRNA into bone mesenchymal stem cells with high efficiency and low cytotoxicity, surpassing the efficiency of the commercial polyethylenimine (25 kD) and Lipofectamine 3000.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141894/1/adbi201700001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141894/2/adbi201700001_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141894/3/adbi201700001-sup-0001-S1.pd

Self‐Assembly of Therapeutic Peptide into Stimuli‐Responsive Clustered Nanohybrids for Cancer‐Targeted Therapy

Clinical translation of therapeutic peptides, particularly those targeting intracellular protein–protein interactions (PPIs), has been hampered by their inefficacious cellular internalization in diseased tissue. Therapeutic peptides engineered into nanostructures with stable spatial architectures and smart disease targeting ability may provide a viable strategy to overcome the pharmaceutical obstacles of peptides. This study describes a strategy to assemble therapeutic peptides into a stable peptide–Au nanohybrid, followed by further self‐assembling into higher‐order nanoclusters with responsiveness to tumor microenvironment. As a proof of concept, an anticancer peptide termed β‐catenin/Bcl9 inhibitors is copolymerized with gold ion and assembled into a cluster of nanohybrids (pCluster). Through a battery of in vitro and in vivo tests, it is demonstrated that pClusters potently inhibit tumor growth and metastasis in several animal models through the impairment of the Wnt/β‐catenin pathway, while maintaining a highly favorable biosafety profile. In addition, it is also found that pClusters synergize with the PD1/PD‐L1 checkpoint blockade immunotherapy. This new strategy of peptide delivery will likely have a broad impact on the development of peptide‐derived therapeutic nanomedicine and reinvigorate efforts to discover peptide drugs that target intracellular PPIs in a great variety of human diseases, including cancer.A strategy for clinical translation of therapeutic peptides by assembling them into a stable peptide–Au nanohybrid, followed by further self‐assembling into higher‐order nanoclusters with responsiveness to the tumor microenvironment, is presented. An anticancer peptide termed β‐catenin/Bcl9 inhibitor is assembled into a cluster of nanohybrids termed pCluster, which potently inhibits tumor growth as well as metastasis, and synergizes with immunotherapy, while maintaining a highly favorable biosafety profile.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148246/1/adfm201807736.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148246/2/adfm201807736-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148246/3/adfm201807736_am.pd

identification of amino acid residues critical for the b cell growth promoting activity of hiv 1 matrix protein p17 variants

Abstract Background HIV-1 matrix protein p17 variants (vp17s) detected in HIV-1-infected patients with non-Hodgkin's lymphoma (HIV-NHL) display, differently from the wild-type protein (refp17), B cell growth-promoting activity. Biophysical analysis revealed that vp17s are destabilized as compared to refp17, motivating us to explore structure-function relationships. Methods We used: biophysical techniques (circular dichroism (CD), nuclear magnetic resonance (NMR) and thermal/GuHCL denaturation) to study protein conformation and stability; Surface plasmon resonance (SPR) to study interactions; Western blot to investigate signaling pathways; and Colony Formation and Soft Agar assays to study B cell proliferation and clonogenicity. Results By forcing the formation of a disulfide bridge between Cys residues at positions 57 and 87 we obtained a destabilized p17 capable of promoting B cell proliferation. This finding prompted us to dissect refp17 to identify the functional epitope. A synthetic peptide (F1) spanning from amino acid (aa) 2 to 21 was found to activate Akt and promote B cell proliferation and clonogenicity. Three positively charged aa (Arg15, Lys18 and Arg20) proved critical for sustaining the proliferative activity of both F1 and HIV-NHL-derived vp17s. Lack of any interaction of F1 with the known refp17 receptors suggests an alternate one involved in cell proliferation. Conclusions The molecular reasons for the proliferative activity of vp17s, compared to refp17, relies on the exposure of a functional epitope capable of activating Akt. General significance Our findings pave the way for identifying the receptor(s) responsible for B cell proliferation and offer new opportunities to identify novel treatment strategies in combating HIV-related NHL

Human enteric a-defensin 5 promotes shigella infection by enhancing bacterial adhesion and invasion

Shigella is a Gram-negative bacterium that causes bacillary dysentery worldwide. It invades the intestinal epithelium to elicit intense inflammation and tissue damage, yet the underlying mechanisms of its host selectivity and low infectious inoculum remain perplexing. Here, we report that Shigella coopts human a-defensin 5 (HD5), a host defense peptide important for intestinal homeostasis and innate immunity, to enhance its adhesion to and invasion of mucosal tissues. HD5 promoted Shigella infection in vitro in a structure-dependent manner. Shigella, commonly devoid of an effective host-adhesion apparatus, preferentially targeted HD5 to augment its ability to colonize the intestinal epithelium through interactions with multiple bacterial membrane proteins. HD5 exacerbated infectivity and Shigella-induced pathology in a culture of human colorectal tissues and three animal models. Our findings illuminate how Shigella exploits innate immunity by turning HD5 into a virulence factor for infection, unveiling a mechanism of action for this highly proficient human pathogen

Crystal structure of master biofilm regulator CsgD regulatory domain reveals an atypical receiver domain

The master regulator CsgD switches planktonic growth to biofilm formation by activating synthesis of curli fimbriae and cellulose in Enterobacteriaceae. CsgD was classified to be the LuxR response regulatory family, while its cognate sensor histidine kinase has not been identified yet. CsgD consists of a C-terminal DNA binding domain and an N-terminal regulatory domain that provokes the upstream signal transduction to further modulate its function. We provide the crystal structure of Salmonella Typhimurium CsgD regulatory domain, which reveals an atypical 55 response regulatory receiver domain folding with the 2 helix representing as a disorder loop compared to the LuxR/FixJ canonical response regulator, and the structure indicated a noteworthy 5 helix similar to the non-canonical master regulator VpsT receiver domain 6. CsgD regulatory domain assembles with two dimerization interfaces mainly through 1 and 5, which has shown similarity to the c-di-GMP independent and stabilized dimerization interface of VpsT from Vibrio cholerae respectively. The potential phosphorylation site D59 is directly involved in the interaction of interfaces I and mutagenesis studies indicated that both dimerization interfaces could be crucial for CsgD activity. The structure reveals important molecular details for the dimerization assembly of CsgD and will shed new insight into its regulation mechanism

Prediction of poor outcome after hypoxic-ischemic brain injury by diffusion-weighted imaging: A systematic review and meta-analysis.

Accurate prediction of the neurological outcome following hypoxic-ischemic brain injury (HIBI) remains difficult. Diffusion-weighted imaging (DWI) can detect acute and subacute brain abnormalities following global cerebral hypoxia. Therefore, DWI can be used to predict the outcomes of HIBI. To this end, we searched the PubMed, EMBASE, and Cochrane Library databases for studies that examine the diagnostic accuracy of DWI in predicting HIBI outcomes in adult patients between January1995 and September 2019. Next, we conducted a comprehensive meta-analysis using the Meta-DiSc and several complementary techniques. Following the application of inclusion and exclusion criteria, a total of 28 studies were included with 98 data subsets. The overall sensitivity and specificity, with 95% confidence interval, were 0.613(0.599-0.628) and 0.958(0.947-0.967), respectively, and the area under the curve was 0.9090. Significant heterogeneity among the included studies and a threshold effect were observed (p<0.001). Different positive indices were the major sources for the heterogeneity, followed by the anatomical region examined, both of which significantly affected the prognostic accuracy. In conclusion, we demonstrated that DWI can be an instrumental modality in predicting the outcome of HIBI with good prognostic accuracy. However, the lack of clear and generally accepted positive indices limits its clinical application. Therefore, using more reliable positive indices and combining DWI with other clinical predictors may improve the diagnostic accuracy of HIBI

Effects of 20 Hz Repetitive Transcranial Magnetic Stimulation on Disorders of Consciousness: A Resting-State Electroencephalography Study

Repetitive transcranial magnetic stimulation (rTMS) has been proposed as an experimental approach for the treatment of disorders of consciousness (DOC). To date, there has been little research into the use of rTMS in DOC and the therapeutic effects have been variously documented. This study aimed to examine the effects of 20 Hz rTMS on the electroencephalography (EEG) reactivity and clinical response in patients with DOC and to explore the neuromodulatory effects of high-frequency rTMS. In this randomized, sham-controlled, crossover study, real or sham 20 Hz rTMS was applied to the left primary motor cortex (M1) of patients with DOC for 5 consecutive days. Evaluations were blindly performed at the baseline (T0), immediately after the end of the 5 days of treatment (T1) and 1 week after the treatment (T2) using the JFK coma recovery scale-revised (CRS-R) and resting-state EEG. Only one patient, with a history of 2 months of traumatic brain injury, showed long-lasting (T1, T2) behavioral and neurophysiological modifications after the real rTMS stimulation. The 5 remaining patients presented brain reactivity localized at several electrodes, and the EEG modification was not significant. rTMS stimulation may improve awareness and arousal of DOC. Additionally, EEG represents a potential biomarker for the therapeutic efficacy of rTMS. This trial is registered with (NCT03385278)

Anomalous efficiency elevation of quantum-dot light-emitting diodes induced by operational degradation.

Acknowledgements: We thank the technical support of Nano-X from Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (SINANO). We thank Dr R. Huang (SINANO) and Ms Z. Li (SINANO) for the ToF-SIMS and XPS characterizations. We acknowledge financial support from the National Key R&D Program of China (2021YFB3602703 and 2022YFB3606503 (Y.J.); 2021YFA1202802 (Q.C.)), National Natural Science Foundation of China (21975220 (Y.J.); 22022205 and 22372193 (Q.C.)), Key Research and Development Program of Zhejiang Province (2020C01001 (Y.J.)), China Postdoctoral Science Foundation (2021M702800 (Y.D.)) and the CAS Project for Young Scientists in Basic Research (YSBR-054 (Q.C.)).Funder: National Key R&D Program of China (2021YFB3602703, 2022YFB3606503) Key Research and Development Program of Zhejiang Province (2020C01001)Funder: National Key R&D Program of China (2021YFA1202802) CAS Project for Young Scientists in Basic Research (YSBR-054)Quantum-dot light-emitting diodes promise a new generation of high-performance and solution-processed electroluminescent light sources. Understanding the operational degradation mechanisms of quantum-dot light-emitting diodes is crucial for their practical applications. Here, we show that quantum-dot light-emitting diodes may exhibit an anomalous degradation pattern characterized by a continuous increase in electroluminescent efficiency upon electrical stressing, which deviates from the typical decrease in electroluminescent efficiency observed in other light-emitting diodes. Various in-situ/operando characterizations were performed to investigate the evolutions of charge dynamics during the efficiency elevation, and the alterations in electric potential landscapes in the active devices. Furthermore, we carried out selective peel-off-and-rebuild experiments and depth-profiling analyses to pinpoint the critical degradation site and reveal the underlying microscopic mechanism. The results indicate that the operation-induced efficiency increase results from the degradation of electron-injection capability at the electron-transport layer/cathode interface, which in turn leads to gradually improved charge balance. Our work provides new insights into the degradation of red quantum-dot light-emitting diodes and has far-reaching implications for the design of charge-injection interfaces in solution-processed light-emitting diodes