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Vertical management auditing reforms achieve the centralization of audit institutions. The centralized structure of the auditing institutions affects their performance. This paper verifies the positive effect of vertical management auditing reform on carbon productivity through a difference-in-differences method. The conclusion still holds after robustness tests. Moreover, the policy effects only make sense when government officials face low promotion pressure or high public scrutiny pressure. The mechanism analysis shows that the vertical management auditing reform can improve carbon productivity by strengthening environmental regulation, promoting industrial structure rationalization, and improving regional green innovation and energy efficiency. This paper enriches the research on the relationship between auditing centralization and carbon productivity. [ABSTRACT FROM AUTHOR]

To explore the effects of bromine domain protein 4 (BRD4) inhibitor JQ1 on the expression profile of super-enhancer-related genes (SE-genes) in cervical cancer (CC) HeLa cells and construct a prognosis model to explore the potential impact of JQ1 on the prognosis of CC. Whole transcriptome sequencing technology was used to detect changes in the gene expression profiles of JQ1-treated and control cells. Differentially expressed SE-genes were identified by matching via the dbCoRC database and Cistrome Data Browser (Cistrome DB). The prognosis of differentially expressed SE-genes was analyzed in the Cancer Genome Atlas (TCGA) dataset based on gene expression status. The Cox proportional risk model and least absolute shrinkage and selection operator (LASSO) regression were used to construct the prognostic model. A total of 1161 SEgenes were identified from dbCoRC and Cistrome DB, among which 1004 SE-genes were successfully matched to the expression profiles of JQ1 transcriptome sequencing. Differential expression analysis identified 110 differentially expressed SE-genes, among which 72 were down-regulated and 38 were upregulated. Then, a 9 SE-gene prognostic model was constructed, and Kaplan-Meier (K-M) curves showed that the high-risk group had significantly poorer clinical survival outcomes (p < 0.05). Time-dependent receiver operating characteristic (ROC) curves showed that the 1-year, 2-year and 3-year survival estimation of the proposed model was 0.82, 0.86 and 0.87, respectively, demonstrating excellent performance. JQ1 significantly impacts the SE-genes expression profile of HeLa cells, and the proposed model based on 9 differentially expressed SE-genes may effectively predict the survival outcomes of CC patients. As this study was based on exploratory analysis, further prospective studies are needed to verify the effectiveness of the SE-genes-based prognostic model. [ABSTRACT FROM AUTHOR]

A model for the evolution of two droplets laden with insoluble surfactant coalescing on a preset film is established according to the lubrication theory, and the coalescence processes are simulated. The role of the surfactant and its inherent mechanism are investigated, the effects of the Marangoni number, the preset liquid film thickness and the initial spacing between the two droplets on the coalescence are examined. The results show that the droplets encounter each other, gradually overlap, and finally coalesce into a "new" droplet. The Marangoni effect is beneficial to the convergence of the two inner leading fronts of the droplets in the early stage, but it hinders the accumulation of the droplets and subsequent coalescence. Increasing the Marangoni number promotes not only the aforementioned inhibition, but also the convergence of the two leading fronts towards the center, which speeds up the coalescence of the surfactant. Moreover, the diffusion of the surfactant towards the outsides of the droplets is accelerated; hence, its distribution along the droplet surface is more uniform after the coalescence. The droplets and the surfactant undertake a longer "journey" to achieve coalescence when their initial spacing is increased; increasing the preset film thickness shortens the time of coalescence required. [ABSTRACT FROM AUTHOR]

Despite extensive studies on the folding and function of cytochrome c, the mechanisms underlying its aggregation remain largely unknown. We herein examined the aggregation behavior of the physiologically relevant two types of cytochrome c, metal-bound cytochrome c, and its fragment with high amyloidogenicity as predicted in alcohol/water mixtures. Although the aggregation propensity of holo cytochrome c was low due to high solubility, markedly unfolded apo cytochrome c, lacking the heme prosthetic group, strongly promoted the propensity for amorphous aggregation with increases in hydrophobicity. Silver-bound apo cytochrome c increased the capacity of fibrillar aggregation (i.e., protofibrils or immature fibrils) due to subtle structural changes of apo cytochrome c by strong binding of silver. However, mature amyloid fibrils were not detected for any of the cytochrome c variants or its fragment, even with extensive ultrasonication, which is a powerful amyloid inducer. These results revealed the intrinsically low amyloidogenicity of cytochrome c, which is beneficial for its homeostasis and function by facilitating the folding and minimizing irreversible amyloid formation. We propose that intrinsically low amyloidogenicity of cytochrome c is attributed to the low metastability of supersaturation. The phase diagram constructed based on solubility and aggregate type is useful for a comprehensive understanding of protein aggregation. Furthermore, amorphous aggregation, which is also viewed as a generic property of proteins, and amyloid fibrillation can be distinguished from each other by the metastability of supersaturation. [ABSTRACT FROM AUTHOR]

LETTER REPLY TO MA AND WANG: Reliabilityofvariousinvitroactivityassayson SARS-CoV-2mainproteaseinhibitors Zhe Li a,1 , Yuxi Lin b,c,1, Yi-You Huang a,1, Runduo Liu a , Chang-Guo Zhan d,e,2 , Xin Wang b,f,2 , and Hai-Bin Luo a,g,2  Ma and Wang (1) tested our recently reported severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) main protease (M pro) noncovalent inhibitors (2) using their in vitro assays, and they obtained negligible or much lower inhibitory activities compared to ours. Notably,thefluorescence resonanceenergytransfer(FRET)-basedenzymaticassay used by Ma and Wang (1) is different from our FRETbased enzymatic assay in the M pro protein (discussed below) and the FRET substrate [longer than the more popularly used substrate (3, 4) utilized in our assay]. Ma and Wang (1) also used native mass spectrometry (MS) and thermal shift assays (TSA) to detect the protein-ligand binding. [Extracted from the article]

Amyloid fibrils and amorphous aggregates are two types of aberrant aggregates associated with protein misfolding diseases. Although they differ in morphology, the two forms are often treated indiscriminately, β2-microglobulin (β2m), a protein responsible for dialysis-related amyloidosis, forms amyloid fibrils or amorphous aggregates depending on the NaCl concentration at pH 2.5. We compared the kinetics of their formation, which was monitored by measuring thioflavin T fluorescence, light scattering, and 8-anilino-1-naphthalenesulfonate fluorescence. Thioflavin T fluorescence specifically monitors amyloid fibrillation, whereas light scattering and 8-anilino-1-naphthalenesulfonate fluorescence monitor both amyloid fibrillation and amorphous aggregation. The amyloid fibrils formed via a nucleation-dependent mechanism in a supersaturated solution, analogous to crystallization. The lag phase of fibrillation was reduced upon agitation with stirring or ultrasonic irradiation, and disappeared by seeding with preformed fibrils. In contrast, the glass-like amorphous aggregates formed rapidly without a lag phase. Neither agitation nor seeding accelerated the amorphous aggregation. Thus, by monitoring the kinetics, we can distinguish between crystal-like amyloid fibrils and glass-like amorphous aggregates. Solubility and supersaturation will be key factors for further understanding the aberrant aggregation of proteins. [ABSTRACT FROM AUTHOR]

The aggregation of amyloid-β (Aβ) on lipid bilayers has been implicated as a mechanism by which Aβ exerts its toxicity in Alzheimer's disease (AD). Lipid bilayer thinning has been observed during both oxidative stress and protein aggregation in AD, but whether these pathological modifications of the bilayer correlate with Aβ misfolding is unclear. Here, we studied peptide-lipid interactions in synthetic bilayers of the shortchain lipid dilauroyl phosphatidylcholine (DLPC) as a simplified model for diseased bilayers to determine their impact on Aβ aggregate, protofibril, and fibril formation. Aβ aggregation and fibril formation in membranes composed of dioleoyl phosphatidylcholine (DOPC) or 1-palmitoyl-2-oleoyl phosphatidylcholine mimicking normal bilayers served as controls. Differences in aggregate formation and stability were monitored by a combination of thioflavin-T fluorescence, circular dichroism, atomic force microscopy, transmission electron microscopy, and NMR. Despite the ability of all three lipid bilayers to catalyze aggregation, DLPC accelerates aggregation at much lower concentrations and prevents the fibrillation of Aβ at low micromolar concentrations. DLPC stabilized globular, membrane-associated oligomers, which could disrupt the bilayer integrity. DLPC bilayers also remodeled preformed amyloid fibrils into a pseudo-unfolded, molten globule state, which resembled on-pathway, protofibrillar aggregates. Whereas the stabilized, membrane-associated oligomers were found to be nontoxic, the remodeled species displayed toxicity similar to that of conventionally prepared aggregates. These results provide mechanistic insights into the roles that pathologically thin bilayers may play in Aβ aggregation on neuronal bilayers, and pathological lipid oxidation may contribute to Aβ misfolding. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global crisis. There is no therapeutic treatment specific for COVID-19. It is highly desirable to identify potential antiviral agents against SARS-CoV-2 from existing drugs available for other diseases and thus repurpose them for treatment of COVID-19. In general, a drug repurposing effort for treatment of a new disease, such as COVID-19, usually starts from a virtual screening of existing drugs, followed by experimental validation, but the actual hit rate is generally rather low with traditional computational methods. Here we report a virtual screening approach with accelerated free energy perturbation-based absolute binding free energy (FEP-ABFE) predictions and its use in identifying drugs targeting SARS-CoV-2 main protease (Mpro). The accurate FEP-ABFE predictions were based on the use of a restraint energy distribution (RED) function, making the practical FEP-ABFE-based virtual screening of the existing drug library possible. As a result, out of 25 drugs predicted, 15 were confirmed as potent inhibitors of SARS-CoV-2 Mpro. The most potent one is dipyridamole (inhibitory constant Ki = 0.04 µM)which has shown promising therapeutic effects in subsequently conducted clinical studies for treatment of patients with COVID-19. Additionally, hydroxychloroquine (Ki = 0.36 µM) and chloroquine (Ki = 0.56 µM) were also found to potently inhibit SARS-CoV-2 Mpro. We anticipate that the FEP-ABFE prediction-based virtual screening approach will be useful in many other drug repurposing or discovery efforts. [ABSTRACT FROM AUTHOR]

Tamoxifen, a widely used modulator of the estrogen receptor (ER), targets ER-positive breast cancer preferentially. We used a powerful validation-based insertion mutagenesis method to find that expression of a dominant-negative, truncated form of the histone deacetylase ZIP led to resistance to tamoxifen. Consistently, increased expression of full-length ZIP gives the opposite phenotype, inhibiting the expression of genes whose products mediate resistance. An important example is JAK2. By binding to two specific sequences in the promoter, ZIP suppresses JAK2 expression. Increased expression and activation of JAK2 when ZIP is inhibited lead to increased STAT3 phosphorylation and increased resistance to tamoxifen, both in cell culture experiments and in a mouse xenograft model. Furthermore, data from human tumors are consistent with the conclusion that decreased expression of ZIP leads to resistance to tamoxifen in ERpositive breast cancer. [ABSTRACT FROM AUTHOR]

As a central feature of neuroinflammation, microglial dysfunction has been increasingly considered a causative factor of neurodegeneration implicating an intertwined pathology with amyloidogenic proteins. Herein, we report the smallest synthetic molecule (N,N′- diacetyl-p-phenylenediamine [DAPPD]), simply composed of a benzene ring with 2 acetamide groups at the para position, known to date as a chemical reagent that is able to promote the phagocytic aptitude ofmicroglia and subsequently ameliorate cognitive defects. Based on our mechanistic investigations in vitro and in vivo, 1) the capability of DAPPD to restore microglial phagocytosis is responsible for diminishing the accumulation of amyloid-β (Aβ) species and significantly improving cognitive function in the brains of 2 types of Alzheimer’s disease (AD) transgenic mice, and 2) the rectification of microglial function by DAPPD is a result of its ability to suppress the expression of NLRP3 inflammasome-associated proteins through its impact on the NF-κB pathway. Overall, our in vitro and in vivo investigations on efficacies andmolecular-level mechanisms demonstrate the ability of DAPPD to regulate microglial function, suppress neuroinflammation, foster cerebral Aβ clearance, and attenuate cognitive deficits in AD transgenic mouse models. Discovery of such antineuroinflammatory compounds signifies the potential in discovering effective therapeutic molecules against AD-associated neurodegeneration. [ABSTRACT FROM AUTHOR]

Amyloid fibrils form in supersaturated solutions via a nucle-ation and growth mechanism. We proposed that ultrasonication may be an effective agitation to trigger nucleation that would otherwise not occur under the persistent metastability of super-saturation. However, the roles of supersaturation and effects of ultrasonication have not been elucidated in detail except for limited cases. Insulin is an amyloidogenic protein that is useful for investigating the mechanisms underlying amyloid fibrillation with biological relevance. We studied the alcohol-induced amyloid fibrillation of insulin using various concentrations of 2,2,2-trifluoroethanol and 1,1,1,3,3,3-hexafluoro-2-propanol at pH 2.0 and 4.8. Ultrasonic irradiation effectively triggered fibrillation under conditions in which insulin retained persistent supersaturation. Structural analyses by circular dichroism, Fourier transform infrared spectroscopy, transmission electron microscopy, and atomic force microscopy revealed that the dominant structures of fibrils varied between parallel and antiparallel β-sheets depending on the solvent conditions. pH and alcohol concentration-dependent phase diagrams showed a marked difference before and after the ultrasonic treatment, which indicated that the persistent metastability of supersaturation determined the conformations of insulin. These results indicate the importance of an alternative view of amyloid fibrils as supersaturation-limited crystal-like aggregates formed above the solubility limit. [ABSTRACT FROM AUTHOR]