Comparison of different hydroxyapatite composites for bone tissue repair: In vitro and in vivo analyses.

Objectives: The material used for bone tissue repair needs to be simultaneously osteoconductive, osteoinductive, and osteogenic. To overcome this problem, researchers combine hydroxyapatite (HA) with natural materials to improve properties. This paper compares the effects of angiogenesis and osteogenesis with different composites through in vivo experiments and characterization analysis. Materials and Methods: Chitosan/nHA (CS/nHA) and sodium alginate/nHA (SA/nHA) microspheres were synthesized via reverse-phase emulsification crosslinking and analyzed using scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), and X-ray diffraction (XRD). Implanted into mouse thigh muscles, their angiogenic and osteogenic potentials were assessed after 8 and 12 weeks through various staining methods and immunohistochemistry. Results: The mean vascular density (MVD) of CS/nHA, CaP/nHA, and SA/nHA groups was (134.92±35.30) n/mm2, (159.09±22.14) n/mm2, (160.31±42.23) n/mm2 at 12 weeks, respectively. The MVD of the CaP/nHA and SA/nHA groups were significantly higher than that of the CS/nHA group. The collagen volume fractions (CVF) were 34.13%, 51.53%, and 54.96% in the CS/nHA, CaP/nHA, and SA/nHA groups, respectively. In addition, the positive expression area ratios of OPN and CD31 in the CaP/nHA and SA/nHA groups were also significantly higher than those in the CS/nHA group. Conclusion: The ability of SA/nHA composite microspheres in osteogenesis and angiogenesis is clearly superior to that of the CS/nHA group and is comparable to that of CaP/nHA, which has superior osteogenesis ability, indicating that SA/nHA composite microspheres have greater application prospects in bone tissue engineering.

Quantification of membrane geometry and protein sorting on cell membrane protrusions using fluorescence microscopy.

Plasma membranes are flexible and can exhibit numerous shapes below the optical diffraction limit. The shape of cell periphery can either induce or be a product of local protein density changes, encoding numerous cellular functions. However, quantifying membrane curvature and the ensuing sorting of proteins in live cells remains technically demanding. Here, we demonstrate the use of simple widefield fluorescence microscopy to study the geometrical properties (i.e., radius, length, and number) of thin membrane protrusions. Importantly, the quantification of protrusion radius establishes a platform for studying the curvature preferences of membrane proteins.

Metaproteomics-informed stoichiometric modeling reveals the responses of wetland microbial communities to oxygen and sulfate exposure.

Climate changes significantly impact greenhouse gas emissions from wetland soil. Specifically, wetland soil may be exposed to oxygen (O2) during droughts, or to sulfate (SO42-) as a result of sea level rise. How these stressors - separately and together - impact microbial food webs driving carbon cycling in the wetlands is still not understood. To investigate this, we integrated geochemical analysis, proteogenomics, and stoichiometric modeling to characterize the impact of elevated SO42- and O2 levels on microbial methane (CH4) and carbon dioxide (CO2) emissions. The results uncovered the adaptive responses of this community to changes in SO42- and O2 availability and identified altered microbial guilds and metabolic processes driving CH4 and CO2 emissions. Elevated SO42- reduced CH4 emissions, with hydrogenotrophic methanogenesis more suppressed than acetoclastic. Elevated O2 shifted the greenhouse gas emissions from CH4 to CO2. The metabolic effects of combined SO42- and O2 exposures on CH4 and CO2 emissions were similar to those of O2 exposure alone. The reduction in CH4 emission by increased SO42- and O2 was much greater than the concomitant increase in CO2 emission. Thus, greater SO42- and O2 exposure in wetlands is expected to reduce the aggregate warming effect of CH4 and CO2. Metaproteomics and stoichiometric modeling revealed a unique subnetwork involving carbon metabolism that converts lactate and SO42- to produce acetate, H2S, and CO2 when SO42- is elevated under oxic conditions. This study provides greater quantitative resolution of key metabolic processes necessary for the prediction of CH4 and CO2 emissions from wetlands under future climate scenarios.

SIVA-1 interaction with PCBP1 serves as a predictive biomarker for cisplatin sensitivity in gastric cancer and its inhibitory effect on tumor growth in vivo.

Background: SIVA-1 has been reported to play a key role in cell apoptosis and gastric cancer (GC) chemoresistance in vitro. Nevertheless, the clinical significance of SIVA-1 in GC chemotherapy remains unclear. Methods and results: Immunohistochemistry and histoculture drug response assays were used to determine SIVA-1 expression and the inhibition rate (IR) of agents to GC and to further analyze the relationship between these two phenomena. Additionally, cisplatin (DDP)-resistant GC cells were used to elucidate the role and mechanism of SIVA-1 in vivo. The results demonstrated that SIVA-1 expression was positively correlated with the IR of DDP to GC but not with those of 5-fluorouracil (5-FU) or adriamycin (ADM). Furthermore, SIVA-1 overexpression with DDP treatment synergistically inhibited tumor growth in vivo by increasing PCBP1 and decreasing Bcl-2 and Bcl-xL expression. Conclusions: Our study demonstrated that SIVA-1 may serve as an indicator of the GC sensitivity to DDP, and the mechanism of SIVA-1 in GC resistance to DDP was preliminarily revealed.

Efficacy and safety analysis of anlotinib in combination with immune checkpoint inhibitors for second-line and subsequent extensive-stage small-cell lung cancer.

Currently, there is a lack of effective second-line and subsequent treatments for patients with extensive-stage small-cell lung cancer (ES-SCLC), and the establishment of a standardized treatment protocol is still underway. Considering the potential synergistic therapeutic effects of anti-angiogenic drugs and immune checkpoint inhibitors (ICIs), combination therapy could be a viable option for treating lung cancer. This research concentrates on assessing the efficacy and safety of anlotinib in combination with ICIs for the treatment of ES-SCLC. We undertook a retrospective analysis of patients with extensive-stage SCLC who received anlotinib in combination with ICIs as second-line and subsequent treatment at Zhejiang Cancer Hospital between April 2020 and April 2023. Survival rates were analyzed using the Kaplan-Meier method. Among the 43 patients who received combination therapy, there were no cases of complete response (CR), 16 patients who achieved partial response (PR), 21 patients who had stable disease (SD), and 6 patients who experienced disease progression (PD). This resulted in an overall response rate (ORR) of 37.2% (16/43) and a disease control rate (DCR) of 86.0% (34/43). The median progression-free survival (PFS) was 4.0 months (95% CI: 2.74-5.26), and the median overall survival (OS) time was 10 months (95% CI: 4.8-15.2). Cox multifactorial regression analysis disclosed that the performance score (PS) and the number of metastatic organs were independent factors influencing PFS in ES-SCLC (p<0.001). The combination therapy demonstrated acceptable toxicity, with a total grade 3/4 toxicity rate of 30.2%. The combination therapy showed a notable association with several adverse events, including hand-foot syndrome, hypertension, and fatigue, which were the most significant. Combining anlotinib with immune checkpoint inhibitors has demonstrated favorable efficacy and safety in the treatment of second-line and subsequent extensive-stage small-cell lung cancer.

Measurement-Based Infused Circuits for Variational Quantum Eigensolvers.

Variational quantum eigensolvers (VQEs) are successful algorithms for studying physical systems on quantum computers. Recently, they were extended to the measurement-based model of quantum computing, bringing resource graph states and their advantages into the realm of quantum simulation. In this Letter, we incorporate such ideas into traditional VQE circuits. This enables novel problem-informed designs and versatile implementations of many-body Hamiltonians. We showcase our approach on real superconducting quantum computers by performing VQE simulations of testbed systems including the perturbed planar code, Z_{2} lattice gauge theory, 1D quantum chromodynamics, and the LiH molecule.

Epidemiological study on seroprevalence of syphilis in patients with mental diseases.

INTRODUCTION: The objective of this study was to investigate the seroprevalence of syphilis and its possible influencing factors in patients with mental illness. METHODOLOGY: A total of 24,414 patients with mental illness from 2019 to 2021 were included. Serum syphilis antibody test results and available demographic data were collected. Chi-square test and regression analysis were used to analyze the data. RESULTS: The seroprevalence of syphilis was 0.59% (95% CI 0.49-0.69%) in patients with mental illness in the study area. There were significant differences in the seroprevalence of syphilis in age, marital status, occupation, urban region, and mental disease classification. The seroprevalence of syphilis increased with age (p < 0.01). The seroprevalence of syphilis was higher in patients with "Nonorganic sleep disorders" and "Reaction to severe stress, and adjustment disorders". Adjusted logistic regression analysis showed that the seroprevalence of syphilis in patients with mental illness was associated with age, region, and psychiatric classification. Older age group was a risk factor for syphilis seropositivity. Compared with schizophrenia, "bipolar affective disorder" (OR = 1.707, 95% CI: 1.017-2.864, p = 0.043) and "severe stress response and adjustment disorders"(R = 4.912, 95% CI: 1.138-21.204, p = 0.033) were risk factors for syphilis antibody positivity. CONCLUSIONS: The patients with "nonorganic sleep disorders" and "reaction to severe stress, and adjustment disorders" had a high seroprevalence of syphilis. Age and psychosis types became the influencing factors of the positive rate of serum syphilis antibody in patients with mental illness.

Optical proximity sensors using multiple quantum well didoes.

InGaN/GaN multiple quantum well (MQW) diodes perform multiple functions, such as optical emission, modulation and reception. In particular, the partially overlapping spectral region between the electroluminescence (EL) and responsivity spectra of each diode results in each diode being able to sense light from another diode of the same MQW structure. Here, we present a noncontact, optical proximity sensing system by integrating an MQW-based light transmitter and detector into a tiny GaN-on-sapphire chip. Changes in the external environment modulate the light emitted from the transmitter. Reflected light is received by the on-chip MQW detector, wherein the carried external modulation information is converted into electrical signals that can be extracted. The maximum detection proximity is approximately 17 mm, and the displacement detection accuracy is within 1 mm. Based on the detection of distance, we extend the application of the sensor to vibration and pressure detection. This monolithic integration design can replace external discrete light transmitter and detector systems to miniaturize reflective sensor architectures, enabling the development of novel optical sensors.

Rotational angle and speed detection via a chip-scale GaN optoelectronic device.

In this paper, a new method for rotational angle and speed measurements is proposed by integrating a GaN optoelectronic chip with a stepped disc. The optoelectronic chip that integrates a light-emitting diode (LED) and a photodiode (PD) is fabricated by wafer-level microfabrication. The disc is designed with a spiral staircase shape, and has increasing thickness distribution along the circumferential direction. The sensing mechanism is that the optoelectronic chip measures angle-dependent intensity change of the light reflected off the stepped disc. Through a series of performance tests, the chip is highly sensitive to a continuous rotation from 0 ∘ to 360 ∘, and produces photocurrent to indicate the rotational angle and speed. A rotational speed up to 5000 rpm is measured with a relative error less than 1.27%. The developed sensing architecture provides an alternative solution for constructing a low-cost, miniaturized, and high-efficiency rotational angle and speed sensing system.

Structural and Biophysical Dynamics of Fungal Plasma Membrane Proteins and Implications for Echinocandin Action in Candida glabrata.

Fungal plasma membrane proteins represent key therapeutic targets for antifungal agents, yet their structure and spatial distribution in the native context remain poorly characterized. Herein, we employ an integrative multimodal approach to elucidate the structural and functional organization of plasma membrane protein complexes in Candida glabrata , focusing on prominent and essential membrane proteins, the polysaccharide synthase ß-(1,3)-glucan synthase (GS) and the proton pump Pma1. Cryo-electron tomography (cryo-ET) and live cell imaging reveal that GS and Pma1 are heterogeneously distributed into distinct plasma membrane microdomains. Treatment with caspofungin, an echinocandin antifungal that targets GS, alters the plasma membrane and disrupts the native distribution of GS and Pma1. Based on these findings, we propose a model for echinocandin action that considers how drug interactions with the plasma membrane environment lead to inhibition of GS. Our work underscores the importance of interrogating the structural and dynamic characteristics of fungal plasma membrane proteins in situ to understand function and facilitate precisely targeted development of novel antifungal therapies.

Effect of temperature on GaN-integrated optical transceiver chips.

The gallium nitride (GaN) integrated optical transceiver chip based on multiple quantum wells (MQW) structure exhibits great promise in the fields of communication and sensing. In this Letter, the effect of ambient temperature on the performance of GaN-integrated optical transceiver chips including a blue MQW light-emitting diode (LED) and a MQW photodiode (PD) is comprehensively studied. Temperature-dependent light-emitting and current-voltage characteristics of the blue MQW LEDs are measured with the ambient temperature ranging from -70°C to 120°C. The experimental results reveal a decline in the electroluminescent (EL) intensity and an obvious redshift in the emission peak wavelength of the LED with increasing ambient temperature. The light detection performance of MQW PD under different temperatures is also measured with the illumination of an external blue MQW LED, indicating an enhancement in the PD sensitivity as the temperature rises. Finally, the temperature effect on the MQW PD under the illumination of the MQW LED on the GaN-integrated optical transceiver chip is characterized, and the PD photocurrent increases with higher ambient temperature. Furthermore, the measured temperature characteristics indicate that the GaN-integrated optical transceiver chip offers a promising application potential for optoelectronic temperature sensor.

Inflammatory proteins may mediate the causal relationship between gut microbiota and inflammatory bowel disease: A mediation and multivariable Mendelian randomization study.

This research investigates the causal relationships among gut microbiota, inflammatory proteins, and inflammatory bowel disease (IBD), including crohn disease (CD) and ulcerative colitis (UC), and identifies the role of inflammatory proteins as potential mediators. Our study analyzed gut microbiome data from 13,266 samples collected by the MiBioGen alliance, along with inflammatory protein data from recent research by Zhao et al, and genetic data on CD and UC from the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC). We used Mendelian randomization (MR) to explore the associations, complemented by replication, meta-analysis, and multivariable MR techniques for enhanced accuracy and robustness. Our analysis employed several statistical methods, including inverse-variance weighting, MR-Egger, and the weighted median method, ensuring comprehensive and precise evaluation. After MR analysis, replication and meta-analysis, we revealed significant associations between 11 types of gut microbiota and 17 inflammatory proteins were associated with CD and UC. Mediator MR analysis and multivariable MR analysis showed that in CD, the CD40L receptor mediated the causal effect of Defluviitaleaceae UCG-011 on CD (mediation ratio 8.3%), and the Hepatocyte growth factor mediated the causal effect of Odoribacter on CD (mediation ratio 18%). In UC, the C-C motif chemokine 4 mediated the causal effect of Ruminococcus2 on UC (mediation ratio 4%). This research demonstrates the interactions between specific gut microbiota, inflammatory proteins, and CD and UC. Furthermore, the CD40L receptor may mediate the relationship between Defluviitaleaceae UCG-011 and CD; the Hepatocyte growth factor may mediate the relationship between Odoribacter and CD; and the C-C motif chemokine 4 may mediate the relationship between Ruminococcus2 and UC. The identified associations and mediation effects offer insights into potential therapeutic approaches targeting the gut microbiome for managing CD and UC.

Relationships Among Serological Indicators and In Vitro High-Throughput Drug Sensitivity Screening Results in Patients with Hepatocellular Carcinoma.

AIM: The purpose of this study was to analyze the relationship between serum indicators and high-throughput drug screening (HDS) results, aiming to achieve specific therapy for hepatocellular carcinoma (HCC). METHODS: This study recruited patients with HCC who underwent surgical resection at the Hepatobiliary Surgery Center of the First Affiliated Hospital of Chongqing Medical University from December 2019 to December 2021. HCC tissues were obtained from patients during surgery and subjected to in vitro cell culture, and then HDS testing was performed on the cultured tissue samples. We used Spearman's correlation analysis to examine the relationships between drug sensitivity results for anti-hepatocellular carcinoma drugs, other antitumor drugs, and serological indicators, the Neutrophil Lymphocyte Ratio (NLR), Platelet Lymphocyte Ratio (PLR), Systemic Immune Inflammatory Index (SII), Systemic Inflammatory Response Index (SIRI), Prognostic Nutritional Index (PNI), and Lymphocyte Monocyte Ratio (LMR). A significant correlation was considered when P<0.05 and |r|>0.40. Furthermore, linear regression analysis was conducted to elucidate the relationship between serological indicators and drug susceptibility, with significant results indicated by P<0.05 and R²≥0.50. RESULTS: In this study, 82 patients with HCC who had undergone hepatectomy and completed in vitro cell culture and HDS testing were evaluated. Using Spearman's correlation with a significance threshold of P<0.05 and |r|>0.40, we identified significant associations between serological indicators and specific drug regimens: NLR correlated with 5-Fluorouracil, 5- Fluorouracil+Calcium folinate (FOLFOX4), and Capecitabine + Cisplatin (XP); PLR with FOLFOX4; SII with XP, FOLFOX4, Doxorubicin + Oxaliplatin (ADM+L-OHP); and SIRI with XP and FOLFOX4. No correlations were found between PNI or LMR and any drug inhibition rates. A comprehensive evaluation using linear regression analysis-which included variables such as sex, age, hepatitis B virus and liver cirrhosis status, size and number of lesions, alphafetoprotein, total bilirubin, albumin, alanine aminotransferase, aspartate aminotransferase, and prothrombin time, alongside NLR, PLR, SII, and SIRI was conducted in relation to drug regimens. This analysis revealed that NLR, SII, and SIRI are significant predictors of FOLFOX4 inhibition rate, while NLR predicts the inhibition rate of XP effectively. However, no significant links were established between molecular targeted drugs, other antitumor drugs, and serological indicators. CONCLUSIONS: NLR, SII, and SIRI were correlated with FOLFOX4, and the higher the values of NLR, SII, and SIRI, the higher the in vitro inhibition of FOLFOX. Also, NLR was correlated with XP, and the higher the value of NLR, the higher the in vitro inhibition of XP.

A Nanoparticle Vaccine Displaying Conserved Epitopes of the Preexisting Neutralizing Antibody Confers Broad Protection against SARS-CoV-2 Variants.

The rapid development of the SARS-CoV-2 vaccine has been used to prevent the spread of coronavirus 2019 (COVID-19). However, the ongoing and future pandemics caused by SARS-CoV-2 variants and mutations underscore the need for effective vaccines that provide broad-spectrum protection. Here, we developed a nanoparticle vaccine with broad protection against divergent SARS-CoV-2 variants. The corresponding conserved epitopes of the preexisting neutralizing (CePn) antibody were presented on a self-assembling Helicobacter pylori ferritin to generate the CePnF nanoparticle. Intranasal immunization of mice with CePnF nanoparticles induced robust humoral, cellular, and mucosal immune responses and a long-lasting immunity. The CePnF-induced antibodies exhibited cross-reactivity and neutralizing activity against different coronaviruses (CoVs). CePnF vaccination significantly inhibited the replication and pathology of SARS-CoV-2 Delta, WIV04, and Omicron strains in hACE2 transgenic mice and, thus, conferred broad protection against these SARS-CoV-2 variants. Our constructed nanovaccine targeting the conserved epitopes of the preexisting neutralizing antibodies can serve as a promising candidate for a universal SARS-CoV-2 vaccine.

Unconventional IFNω-like Genes Dominate the Type I IFN Locus and the Constitutive Antiviral Responses in Bats.

Bats are the natural reservoir hosts of some viruses, some of which may spill over to humans and cause global-scale pandemics. Different from humans, bats may coexist with high pathogenic viruses without showing symptoms of diseases. As one of the most important first defenses, bat type I IFNs (IFN-Is) were thought to play a role during this virus coexistence and thus were studied in recent years. However, there are arguments about whether bats have a contracted genome locus or constitutively expressed IFNs, mainly due to species-specific findings. We hypothesized that because of the lack of pan-bat analysis, the common characteristics of bat IFN-Is have not been revealed yet. In this study, we characterized the IFN-I locus for nine Yangochiroptera bats and three Yinpterochiroptera bats on the basis of their high-quality bat genomes. We also compared the basal expression in six bats and compared the antiviral and antiproliferative activity and the thermostability of representative Rhinolophus bat IFNs. We found a dominance of unconventional IFNω-like responses in the IFN-I system, which is unique to bats. In contrast to IFNα-dominated IFN-I loci in the majority of other mammals, bats generally have shorter IFN-I loci with more unconventional IFNω-like genes (IFNω or related IFNαω), but with fewer or even no IFNα genes. In addition, bats generally have constitutively expressed IFNs, the highest expressed of which is more likely an IFNω-like gene. Likewise, the highly expressed IFNω-like protein also demonstrated the best antiviral activity, antiproliferative activity, or thermostability, as shown in a representative Rhinolophus bat species. Overall, we revealed pan-bat unique, to our knowledge, characteristics in the IFN-I system, which provide insights into our understanding of the innate immunity that contributes to a special coexistence between bats and viruses.

Individual virome analysis reveals the general co-infection of mammal-associated viruses with SARS-related coronaviruses in bats.

Bats are the natural reservoir hosts for SARS-related coronavirus (SARSr-CoV) and other highly pathogenic microorganisms. Therefore, it is conceivable that an individual bat may harbor multiple microbes. However, there is limited knowledge on the overall co-circulation of microorganisms in bats. Here, we conducted a 16-year monitoring of bat viruses in south and central China and identified 238 SARSr-CoV positive samples across nine bat species from ten provinces or administrative districts. Among these, 76 individual samples were selected for further metagenomics analysis. We found a complex microenvironment characterized by the general co-circulation of microbes from two different sources: mammal-associated viruses or environment-associated microbes. The later includes commensal bacteria, enterobacteria-related phages, and insect or fungal viruses of food origin. Results showed that 25% (19/76) of the samples contained at least one another mammal-associated virus, notably alphacoronaviruses (13/76) such as AlphaCoV/YN2012, HKU2-related CoV and AlphaCoV/Rf-HuB2013, along with viruses from other families. Notably, we observed three viruses co-circulating within a single bat, comprising two coronavirus species and one picornavirus. Our analysis also revealed the potential presence of pathogenic bacteria or fungi in bats. Furthermore, we obtained 25 viral genomes from the 76 bat SARSr-CoV positive samples, some of which formed new evolutionary lineages. Collectively, our study reveals the complex microenvironment of bat microbiome, facilitating deeper investigations into their pathogenic potential and the likelihood of cross-species transmission.

Epitope mapping and establishment of a blocking ELISA for mAb targeting the p72 protein of African swine fever virus.

The African swine fever virus (ASFV) has the ability to infect pigs and cause a highly contagious acute fever that can result in a mortality rate as high as 100%. Due to the viral epidemic, the pig industry worldwide has suffered significant financial setbacks. The absence of a proven vaccine for ASFV necessitates the development of a sensitive and reliable serological diagnostic method, enabling laboratories to effectively and expeditiously detect ASFV infection. In this study, four strains of monoclonal antibodies (mAbs) against p72, namely, 5A1, 4C4, 8A9, and 5E10, were generated through recombinant expression of p72, the main capsid protein of ASFV, and immunized mice with it. Epitope localization was performed by truncated overlapping polypeptides. The results indicate that 5A1 and 4C4 recognized the amino acid 20-39 aa, 8A9 and 5E10 are recognized at 263-282 aa, which is consistent with the reported 265-280 aa epitopes. Conserved analysis revealed 20-39 aa is a high conservation of the epitopes in the ASFV genotypes. Moreover, a blocking ELISA assay for detection ASFV antibody based on 4C4 monoclonal antibody was developed and assessed. The receiver-operating characteristic (ROC) was performed to identify the best threshold value using 87 negative and 67 positive samples. The established test exhibited an area under the curve (AUC) of 0.9997, with a 95% confidence interval ranging from 99.87 to 100%. Furthermore, the test achieved a diagnostic sensitivity of 100% (with a 95% confidence interval of 95.72 to 100%) and a specificity of 98.51% (with a 95% confidence interval of 92.02 to 99.92%) when the threshold was set at 41.97%. The inter- and intra-batch coefficient of variation were below 10%, demonstrating the exceptional repeatability of the method. This method can detect the positive standard serum at a dilution as high as 1:512. Subsequently, an exceptional blocking ELISA assay was established with high diagnostic sensitivity and specificity, providing a novel tool for detecting ASFV antibodies. KEY POINTS: • Four strains of ASFV monoclonal antibodies against p72 were prepared and their epitopes were identified. • Blocking ELISA method was established based on monoclonal antibody 4C4 with an identified conservative epitope. • The established blocking ELISA method has a good effect on the detection of ASFV antibody.

The lethal K18-hACE2 knock-in mouse model mimicking the severe pneumonia of COVID-19 is practicable for antiviral development.

Animal models of COVID-19 facilitate the development of vaccines and antivirals against SARS-CoV-2. The efficacy of antivirals or vaccines may differ in different animal models with varied degrees of disease. Here, we introduce a mouse model expressing human angiotensin-converting enzyme 2 (ACE2). In this model, ACE2 with the human cytokeratin 18 promoter was knocked into the Hipp11 locus of C57BL/6J mouse by CRISPR - Cas9 (K18-hACE2 KI). Upon intranasal inoculation with high (3 × 105 PFU) or low (2.5 × 102 PFU) dose of SARS-CoV-2 wildtype (WT), Delta, Omicron BA.1, or Omicron BA.2 variants, all mice showed obvious infection symptoms, including weight loss, high viral loads in the lung, and interstitial pneumonia. 100% lethality was observed in K18-hACE2 KI mice infected by variants with a delay of endpoint for Delta and BA.1, and a significantly attenuated pathogenicity was observed for BA.2. The pneumonia of infected mice was accompanied by the infiltration of neutrophils and pulmonary fibrosis in the lung. Compared with K18-hACE2 Tg mice and HFH4-hACE2 Tg mice, K18-hACE2 KI mice are more susceptible to SARS-CoV-2. In the antivirals test, REGN10933 and Remdesivir had limited antiviral efficacies in K18-hACE2 KI mice upon the challenge of SARS-CoV-2 infections, while Nirmatrelvir, monoclonal antibody 4G4, and mRNA vaccines potently protected the mice from death. Our results suggest that the K18-hACE2 KI mouse model is lethal and stable for SARS-CoV-2 infection, and is practicable and stringent to antiviral development.

Development of a Menglà virus minigenome and comparison of its polymerase complexes with those of other filoviruses.

Ebola virus (EBOV) and Marburg virus (MARV), members of the Filoviridae family, are highly pathogenic and can cause hemorrhagic fevers, significantly impacting human society. Bats are considered reservoirs of these viruses because related filoviruses have been discovered in bats. However, due to the requirement for maximum containment laboratories when studying infectious viruses, the characterization of bat filoviruses often relies on pseudoviruses and minigenome systems. In this study, we used RACE technology to sequence the 3'-leader and 5'-trailer of Menglà virus (MLAV) and constructed a minigenome. Similar to MARV, the transcription activities of the MLAV minigenome are independent of VP30. We further assessed the effects of polymorphisms at the 5' end on MLAV minigenome activity and identified certain mutations that decrease minigenome reporter efficiency, probably due to alterations in the RNA secondary structure. The reporter activity upon recombination of the 3'-leaders and 5'-trailers of MLAV, MARV, and EBOV with those of the homologous or heterologous minigenomes was compared and it was found that the polymerase complex and leader and trailer sequences exhibit intrinsic specificities. Additionally, we investigated whether the polymerase complex proteins from EBOV and MARV support MLAV minigenome RNA synthesis and found that the homologous system is more efficient than the heterologous system. Remdesivir efficiently inhibited MLAV as well as EBOV replication. In summary, this study provides new information on bat filoviruses and the minigenome will be a useful tool for high-throughput antiviral drug screening.

Berberine improves cognitive impairment by alleviating brain atrophy and promoting white matter reorganization in diabetic db/db mice: a magnetic resonance imaging-based study.

Diabetic cognitive impairment is a common complication in type 2 diabetes. Berberine (BBR) is an isoquinoline alkaloid that has been shown to have neuroprotective effects against diabetes. This study aimed to investigate the effect of BBR on the gray and white matter of the brain by using magnetic resonance imaging (MRI) and to explore the underlying mechanisms. The study used diabetic db/db mice and administered BBR (50 and 100 mg/kg) intragastrically for twelve weeks. Morris water maze was applied to examine cognitive function. T2-weighted imaging (T2WI) was performed to assess brain atrophy, and diffusion tensor imaging (DTI) combined with fiber tracking was conducted to monitor the structural integrity of the white matter, followed by histological immunostaining. Furthermore, the protein expressions of the phosphatidylinositol 3-kinase (PI3K)/ protein kinase B (AKT)/ glycogen synthase kinase-3ß (GSK-3ß) were detected. The results revealed that BBR significantly improved the spatial learning and memory of the db/db mice. T2WI exhibited ameliorated brain atrophy in the BBR-treated db/db mice, as evidenced by reduced ventricular volume accompanied by increased hippocampal volumes. DTI combined with fiber tracking revealed that BBR increased FA, fiber density and length in the corpus callosum/external capsule of the db/db mice. These imaging findings were confirmed by histological immunostaining. Notably, BBR significantly enhanced the protein levels of phosphorylated AKT at Ser473 and GSK-3ß at Ser9. Collectively, this study demonstrated that BBR significantly improved the cognitive function of the diabetic db/db mice through ameliorating brain atrophy and promoting white matter reorganization via AKT/GSK-3ß pathway.