Loss of NAT10 Reduces the Translation of Kmt5a mRNA Through ac4C Modification in Cardiomyocytes and Induces Heart Failure.

BACKGROUND: In the past decade, the biological functions of various RNA modifications in mammals have been uncovered. N4-acetylcytidine (ac4C), a highly conserved RNA modification, has been implicated in human diseases. Despite this, the involvement of RNA ac4C modification in cardiac physiology and pathology remains incompletely understood. NAT10 (N-acetyltransferase 10) stands as the sole acetyltransferase known to catalyze RNA ac4C modification. This study aims to explore the role of NAT10 and ac4C modification in cardiac physiology and pathology. METHODS AND RESULTS: Cardiac-specific knockout of NAT10, leading to reduced RNA ac4C modification, during both neonatal and adult stages resulted in severe heart failure. NAT10 deficiency induced cardiomyocyte apoptosis, a crucial step in heart failure pathogenesis, supported by in vitro data. Activation of the p53 signaling pathway was closely associated with enhanced apoptosis in NAT10-deficient cardiomyocytes. As ac4C modification on mRNA influences translational efficiency, we employed ribosome footprints coupled with RNA sequencing to explore genome-wide translational efficiency changes caused by NAT10 deficiency. We identified and validated that the translational efficiency of Kmt5a was suppressed in NAT10 knockout hearts due to reduced ac4C modification on its mRNA. This finding was consistent with the observation that Kmt5a protein levels were reduced in heart failure despite unchanged mRNA expression. Knockdown of Kmt5a in cardiomyocytes recapitulated the phenotype of NAT10 deficiency, including increased cardiomyocyte apoptosis and activated p53 signaling. Finally, overexpression of Kmt5a rescued cardiomyocyte apoptosis and p53 activation induced by NAT10 inhibition. CONCLUSIONS: Our study highlights the significance of NAT10 in cardiomyocyte physiology, demonstrating that NAT10 loss is sufficient to induce cardiomyocyte apoptosis and heart failure. NAT10 regulates the translational efficiency of Kmt5a, a key mediator, through mRNA ac4C modification during heart failure.

PCSK9 inhibitor attenuates cardiac fibrosis in reperfusion injury rat by suppressing inflammatory response and TGF-ß1/Smad3 pathway.

Progressive cardiac fibrosis, a hallmark of heart failure, remains poorly understood regarding Proprotein convertase subtilisin/kexin type 9 (PCSK9) 's role. This study aims to elucidate PCSK9's involvement in cardiac fibrosis. After ischemia/reperfusion (I/R) injury surgery in rats, PCSK9 inhibitors were used to examine their effects on the transforming growth factor-ß1 (TGF-ß1)/small mother against decapentaplegic 3 (Smad3) pathway and inflammation. Elevated PCSK9, TGF-ß1, and Smad3 levels were observed in cardiac tissues post-I/R injury, indicating fibrosis. PCSK9 inhibition reduced pro-fibrotic protein expression, protecting the heart and mitigating I/R-induced damage and fibrosis. Additionally, it ameliorated cardiac inflammation and reduced post-myocardial infarction (MI) size, improving cardiac function and slowing heart failure progression. PCSK9 inhibitors significantly attenuate myocardial fibrosis induced by I/R via the TGF-ß1/Smad3 pathway.

The latest developments in the design and discovery of non-nucleoside reverse transcriptase inhibitors (NNRTIs) for the treatment of HIV.

INTRODUCTION: This review encapsulates the recent strides in the development of non-nucleoside reverse transcriptase inhibitors (NNRTIs) for HIV treatment, focusing on the novel structural designs that promise to overcome limitations of existing therapies, such as drug resistance and toxicity. AREAS COVERED: We underscore the application of computational chemistry and structure-based drug design in refining NNRTIs with enhanced potency and safety. EXPERT OPINION: Highlighting the emergence of diverse chemical scaffolds like diarylpyrimidines, indoles, DABOs and HEPTs, the review reveals compounds with nanomolar efficacy and improved pharmacokinetics. The integration of artificial intelligence in drug discovery is poised to accelerate the evolution of NNRTIs, laying the foundation for addressing drug resistance in the era of anti-HIV therapy through innovative designs and multi-target strategies.

Identification of novel diarylpyrimidine derivatives as potent HIV-1 non-nucleoside reverse transcriptase inhibitors against wild-type and K103N mutant viruses.

HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) play a crucial role in combination antiretroviral therapy (cART). To further enhance their antiviral activity and anti-resistance properties, we developed a series of novel NNRTIs, by specifically targeting tolerant region I of the NNRTI binding pocket. Among them, compound 9t-2 displayed excellent anti-HIV-1 potency against wild-type and prevalent mutant strains with EC50 values between 0.0019 and 0.012 µM. This outperformed the positive drugs ETR, NVP and RPV. Aslo, ELISA results confirmed that these compounds can effectively inhibit the activity of HIV-1 RT. Molecular dynamics (MD) simulation studies indicated that the thiomorpholine-1,1-dioxide moiety of 9t-2 is capable of establishing additional interactions with residues P225, F227 and P236 in the tolerant region I, which contributed to its enhanced activity. Compound 9t-2 possessed negligible inhibitory effect on the five main CYP isoenzymes (IC50 > 10 µM), indicating a low potential for inducing CYP-mediated drug-drug interactions. In conclusion, compound 9t-2, with its enhanced anti-resistance properties, stands out as a promising lead compound for further optimization towards discovering the new generation of anti-HIV agents.

Anticancer Drug Discovery from Natural Compounds Targeting PI3K/AKT/mTOR Signaling Pathway.

The term cancer is used to describe a complex pathology characterized by the uncontrollable proliferation of cells, which displays a fast metastatic spread, being a disease with difficult treatment. In this context, Phosphatidylinositol 3-kinase (PI3K) represents a promising pathway to be inhibited, aiming to develop anticancer agents, since it performs a pivotal role in regulating essential cellular processes, including cell proliferation, growth, autophagy, and apoptosis. In parallel, natural compounds can effectively represent a therapeutic strategy to fight against malignant cells. Then, compounds derived from various plant sources, such as flavonoids, terpenoids, alkaloids, coumarins, and lignans, have exhibited remarkable in vitro and in vivo anticancer properties. This review focused in the exploration of natural products targeting the PI3K/AKT/m-TOR signaling pathway, demonstrating that these compounds could even further investigated to reveal novel and effective anticancer drugs in the future.

Molecular basis of the urate transporter URAT1 inhibition by gout drugs.

Hyperuricemia is a condition when uric acid, a waste product of purine metabolism, accumulates in the blood1. Untreated hyperuricemia can lead to crystal formation of monosodium urate in the joints, causing a painful inflammatory disease known as gout. These conditions are associated with many other diseases and affect a significant and increasing proportion of the population2-4. The human urate transporter 1 (URAT1) is responsible for the reabsorption of ~90% of uric acid in the kidneys back into the blood, making it a primary target for treating hyperuricemia and gout5. Despite decades of research and development, clinically available URAT1 inhibitors have limitations because the molecular basis of URAT1 inhibition by gout drugs remains unknown5. Here we present cryo-electron microscopy structures of URAT1 alone and in complex with three clinically relevant inhibitors: benzbromarone, lesinurad, and the novel compound TD-3. Together with functional experiments and molecular dynamics simulations, we reveal that these inhibitors bind selectively to URAT1 in inward-open states. Furthermore, we discover differences in the inhibitor dependent URAT1 conformations as well as interaction networks, which contribute to drug specificity. Our findings illuminate a general theme for URAT1 inhibition, paving the way for the design of next-generation URAT1 inhibitors in the treatment of gout and hyperuricemia.

Viral Protein Dimerization Quality Control: A Design Strategy for a Potential Viral Inhibitor.

The global pharmaceutical market has been profoundly impacted by the coronavirus pandemic, leading to an increased demand for specific drugs. Consequently, drug resistance has prompted continuous innovation in drug design strategies to effectively combat resistant pathogens or disease variants. Protein dimers play crucial roles in vivo, including catalytic reactions, signal transduction, and structural stability. The site of action for protein dimerization modulators typically does not reside within the active site of the protein, thereby potentially impeding resistance development. Therefore, harnessing viral protein dimerization modulators could represent a promising avenue for combating viral infections. In this Perspective, we provide a detailed introduction to the design principles and applications of dimerization modulators in antiviral research. Furthermore, we analyze various representative examples to elucidate their modes of action while presenting our perspective on dimerization modulators along with the opportunities and challenges associated with this groundbreaking area of investigation.

[Spatial distribution of soil microorganisms in the Zoige Plateau peatland, Southwest China]. / 若尔盖高原泥炭沼泽土壤微生物空间分布.

Understanding the composition and spatial distribution patterns of microbial communities in plateau peatland soils is crucial for preserving the structural and functional stability of highland wetlands. We collected 50 soil samples from the core conservation area of Zoige peatland along horizontal and vertical distributions to analyze the soil bacterial and fungal diversity by using high-throughput sequencing technology, combined with Mantel tests and multiple regression on matrices (MRM) statistical methods, as well as the spatial distribution characteristics of community structure similarity at a local scale. The results showed that the dominant soil bacterial and fungal groups were Chloroflexi (accounting for 33.2% and 25.1% of the total bacterial community in horizontal and vertical directions, respectively) and Ascomycota (54.7% and 76.4%). The similarity of microbial community structure in both horizontal and vertical directions decreased with increasing spatial distance of the sampling points. The turnover rates of bacterial and fungal communities in the vertical direction were 8.8 and 8.6 times as those in the horizontal direction, respectively. Based on the relative abundance of the communities, we classified microbes into six groups. As the number of rare species in the community increased, the slope of community distance decay decreased. The conditionally rare or abundant taxa (CRAT) category group showed the most similar spatial distribution characteristics to the total microbial community. Mantel analysis indicated that soil organic carbon, total nitrogen, and available phosphorus were key factors driving the distribution of bacterial and fungal communities in the horizontal direction, while soil organic carbon, available carbon, pH, and soil bulk density were the main factors determining the vertical distribution. MRM analysis further showed that both soil physicochemical indicators and spatial distance significantly affected the assembly of microbial communities, where soil factors explained more about the vertical distribution of microbial communities than the horizontal distribution. The impact of soil factors on microbial community distribution was much greater than that of spatial factors through diffusion limitation. In summary, the microbial communities in the plateau peatland soils exhibited more pronounced vertical distribution differences and environmental response characteristics.

Rationally Engineering a Quasi-Solid-State Flexible Self-Healing Secondary Battery Using Hydrogel-Based Water-in-Salt Electrolyte and Electrochemically Deposited Electrodes.

High safety and low cost are essential for energy-storage systems. Here, an aqueous zinc ion battery composed of a hydrogel-based water-in-salt electrolyte prepared by photoinitiated polymerization of acrylamide in ZnCl2 solution (named as PZC) and flexible electrodes is developed. The stable performance in Zn||Zn symmetric cells and high Coulombic efficiency of PZC in Zn||Cu asymmetric cells verify dendrite suppression. VO2 nanobelts coated with polyaniline (PANI) are grown on a carbon cloth (CC). The battery shows a capacity of 221.5 mAh g-1 after 200 cycles. The batteries present high recovery performance after bending/cutting. After bending of 60°, 90°, and 180°, capacities remain at 240.0, 205.4, and 175.2 mAh g-1, respectively; while the battery healed from 1, 2, 3, and 4 times of cutting shows 197.5, 174.3, 124.7, and 101.2 mAh g-1, respectively. Our findings enable the engineering of a quasi-solid-state battery to have good capability for flexible and portable electronics.

Highly efficient activation of peroxymonosulfate via KOH-activated Fe@NC for the degradation of bisphenol A.

In this study, the KOH-modified Fe-ZIF-derived carbon materials (Fe@NC-KOH-x) were designed for Fenton-like systems to enhance bisphenol A (BPA) removal from wastewater. Compared with the Fe@NC without KOH activation, the pore structure, BET (Brunner-Emmet-Teller) surface area, and oxygen-containing functional group of KOH-activated Fe@NC-KOH-x are dramatically improved, which increases the adsorption and catalytic performance. The Fe@NC-KOH-900/PMS system showed significant BPA removal reactivity across wide pH ranges and low doses of Fe@NC-KOH-900. Interestingly, our findings indicated that the removal effectiveness of BPA improved when PMS was introduced following the saturation adsorption of Fe@NC-KOH-x, as compared to the simultaneous introduction of Fe@NC-KOH-x and PMS. More particularly, through regression analysis, we found that the proportion of reactive species in the Fe@NC-KOH-x/PMS system changes with the increase of pyrolysis temperature, and there was a certain relationship between structure-function and active species in the Fe@NC-KOH-x/PMS system. O-C = O, Fe-N4, C-O, and pyrrolic N in Fe@NC-KOH-x lead to the generation of •OH, and SO4-•, C = O, Fe-N4, and defect are closely related to FeIV = O, and the formation of 1O2 is affected by Fe-N4, graphite N, C = O, and defect. Also, the density functional theory (DFT) calculation and the potential correlation between catalyst active centers and reactive oxygen species indicate that Fe-N4 is the main active site of Fe@NC-KOH-x. These outcomes of the study offer an innovation for enhanced elimination of BPA in wastewater treatment and provide a dynamic understanding of the mechanism of BPA degradation.

Miniaturized Modular Click Chemistry-enabled Rapid Discovery of Unique SARS-CoV-2 Mpro Inhibitors With Robust Potency and Drug-like Profile.

The COVID-19 pandemic has required an expeditious advancement of innovative antiviral drugs. In this study, focused compound libraries are synthesized in 96- well plates utilizing modular click chemistry to rapidly discover potent inhibitors targeting the main protease (Mpro) of SARS-CoV-2. Subsequent direct biological screening identifies novel 1,2,3-triazole derivatives as robust Mpro inhibitors with high anti-SARS-CoV-2 activity. Notably, C5N17B demonstrates sub-micromolar Mpro inhibitory potency (IC50 = 0.12 µM) and excellent antiviral activity in Calu-3 cells determined in an immunofluorescence-based antiviral assay (EC50 = 0.078 µM, no cytotoxicity: CC50 > 100 µM). C5N17B shows superior potency to nirmatrelvir (EC50 = 1.95 µM) and similar efficacy to ensitrelvir (EC50 = 0.11 µM). Importantly, this compound displays high antiviral activities against several SARS-CoV-2 variants (Gamma, Delta, and Omicron, EC50 = 0.13 - 0.26 µM) and HCoV-OC43, indicating its broad-spectrum antiviral activity. It is worthy that C5N17B retains antiviral activity against nirmatrelvir-resistant strains with T21I/E166V and L50F/E166V mutations in Mpro (EC50 = 0.26 and 0.15 µM, respectively). Furthermore, C5N17B displays favorable pharmacokinetic properties. Crystallography studies reveal a unique, non-covalent multi-site binding mode. In conclusion, these findings substantiate the potential of C5N17B as an up-and-coming drug candidate targeting SARS-CoV-2 Mpro for clinical therapy.

Synergistic activity of an RNA polymerase PA-PB1 interaction inhibitor with oseltamivir against human and avian influenza viruses in cell culture and in ovo.

In search of novel therapeutic options to treat influenza virus (IV) infections, we previously identified a series of inhibitors that act by disrupting the interactions between the PA and PB1 subunits of the viral RNA polymerase. These compounds showed broad-spectrum antiviral activity against human influenza A and B viruses and a high barrier to the induction of drug resistance in vitro. In this short communication, we investigated the effects of combinations of the PA-PB1 interaction inhibitor 54 with oseltamivir carboxylate (OSC), zanamivir (ZA), favipiravir (FPV), and baloxavir marboxil (BXM) on the inhibition of influenza A and B virus replication in vitro. We observed a synergistic effect of the 54/OSC and 54/ZA combinations and an antagonistic effect when 54 was combined with either FPV or BXM. Moreover, we demonstrated the efficacy of 54 against highly pathogenic avian influenza viruses (HPAIVs) both in cell culture and in the embryonated chicken eggs model. Finally, we observed that 54 enhances OSC protective effect against HPAIV replication in the embryonated eggs model. Our findings represent an advance in the development of alternative therapeutic strategies against both human and avian IV infections.

Clinical trial of arthroscopic debridement combined with functional exercise in the treatment of advanced knee osteoarthritis: A retrospective observational study.

BACKGROUND: Advanced knee osteoarthritis (KOA) impacts both knees, resulting in pain, deformity, and substantial restrictions in joint mobility. OBJECTIVE: This study aims to examine the effectiveness of combining arthroscopic debridement with functional exercise in treating advanced KOA. METHODS: A total of 296 patients diagnosed with advanced KOA were divided into two groups: the observation group (n= 152) received arthroscopic debridement combined with functional exercise, while the control group (n= 144) underwent arthroscopic debridement only. The study compared and observed the outcomes between the two groups. RESULTS: There were no significant differences in knee joint function, inflammation level, and oxidative stress between the two groups before treatment (P> 0.05). Following treatment for six months, the observation group exhibited significantly lower visual analog scale (VAS) score, tissue inhibitors of metalloproteinase-1 (TIMP-1), tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), matrix metalloproteinase-3 (MMP-3), and malondialdehyde (MDA) levels compared to the control group (P< 0.05). Meanwhile, the observation group showed significantly higher levels of Lysholm score, hospital for special surgery (HSS) score, range of motion (ROM) of knee, peak torque (PT) and total work (TW) for knee extension and flexion, superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and glutathione (GSH) compared to the control group (P< 0.05). Besides, the effective treatment rate in the observation group was notably higher than that in the control group (80.92% vs. 69.44%, P< 0.05). CONCLUSION: The combination of arthroscopic debridement with functional exercise is an effective treatment for advanced KOA. This approach not only enhances the function and strength of knee joint and reduces inflammatory response but also boosts the body's antioxidant capacity. The treatment exhibits encouraging outcomes and warrants broad implementation.

[Analysis of Antibiotic Resistance of Bioaerosols from Wastewater Treatment Process].

To explore the prevalence and source of antibiotic resistant genes （ARGs） and pathogenic antibiotic resistant bacteria （PARB） associated with bioaerosols in wastewater treatment plants （WWTPs）, metagenomic sequencing and assembly were applied to elucidate the antibiotic resistome of bioaerosols and wastewater in WWTPs. The results showed that more subtypes of ARGs and a higher abundance of PARB were found in bioaerosols from WWTPs and downwind than those from upwind. Multidrug and macB were respectively the most dominant type and subtype of ARGs in bioaerosols from WWTPs. In total, 37 types of PARB carried at least two or more ARG types and were characterized by multiple drug resistance. At the fine grid, aerated tank, and sludge dewatering room, wastewater was the main source of bioaerosol ARGs and PARB. A total of 32 PARB were easily aerosolized in at least one wastewater treatment unit, such as Pseudomonas aeruginosa and Escherichia coli. This study will provide theoretical support for the risk assessment and health protection of antibiotic resistant pollution associated with bioaerosols from WWTPs.

Discovery of 2,4,6-trisubstituted pyrimidine derivatives as novel potent HIV-1 NNRTIs by exploiting the tolerant region II of the NNIBP.

The rapid emergence of drug resistance severely reduces the clinical response of human immunodeficiency virus-1 (HIV-1) to non-nucleoside reverse transcriptase inhibitors (NNRTIs). Herein, a series of 2,4,6-trisubstituted pyrimidine derivatives was designed and synthesized, with the aim to identify novel anti-HIV-1 agents with improved drug resistance profiles. The antiviral activity results demonstrated that all compounds showed excellent potency to wild-type (WT) HIV-1 strain (EC50 = 3.61-15.5 nM). Moreover, 13c was proved to be the most potent inhibitor against the whole tested viral panel, with EC50 ranging from 4.68 to 229 nM. In addition, 13c yielded moderate HIV-1 RT inhibition with IC50 value of 0.231 µM, which demonstrated it was a classical NNRTI. Molecular docking was further conducted to illustrate its binding mode with HIV-1 RT. These encouraging results indicated that 13c can be used as a lead compound for further study.

Discovery of potent HIV-1 NNRTIs by CuAAC click-chemistry-based miniaturized synthesis, rapid screening and structure optimization.

In addressing the urgent need for novel HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) to combat drug resistance, we employed CuAAC click chemistry to construct a diverse 312-member diarylpyrimidine (DAPY) derivative library. This rapid synthesis approach facilitated the identification of A6N36, demonstrating exceptional HIV-1 RT inhibitory activity. Moreover, it was demonstrated with EC50 values of 1.8-8.7 nM for mutant strains L100I, K103 N, Y181C, and E138K, being equipotent or superior to that of ETR. However, A6N36's efficacy was compromised against specific resistant strains (Y188L, F227L + V106A and RES056), highlighting a need for further optimization. Through scaffold hopping, we optimized this lead to develop 10c, which exhibited broad-spectrum activity with EC50 values ranging from 3.2 to 57.5 nM and superior water solubility. Molecular docking underscored the key interactions of 10c within the NNIBP. Our findings present 10c as a promising NNRTI lead, illustrating the power of click chemistry and rational design in combatting HIV-1 resistance.

Discovery of Novel Amino Acids (Analogues)-Substituted Thiophene[3,2-d]pyrimidine Derivatives as Potent HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors: Design, Synthesis, and Biological Evaluation.

Inspired by our previous work on the modification of diarylpyrimidine-typed non-nucleoside reverse transcriptase inhibitors (NNRTIs) and the reported crystallographic studies, a series of novel amino acids (analogues)-substituted thiophene[3,2-d]pyrimidine derivatives were designed and synthesized by targeting the solvent-exposed region of the NNRTI-binding pocket. The biological evaluation results showed that compound 5k was the most active inhibitor, exhibiting moderate-to-excellent potency against HIV-1 wild-type (WT) and a panel of NNRTI-resistant strains, with EC50 values ranging from 0.042 µM to 7.530 µM. Of special note, 5k exhibited the most potent activity against single-mutant strains (K103N and E138K), with EC50 values of 0.031 µM and 0.094 µM, being about 4.3-fold superior to EFV (EC50 = 0.132 µM) and 1.9-fold superior to NVP (EC50 = 0.181 µM), respectively. In addition, 5k demonstrated lower cytotoxicity (CC50 = 27.9 µM) and higher selectivity index values. The HIV-1 reverse transcriptase (RT) inhibition assay was further performed to confirm their binding target. Moreover, preliminary structure-activity relationships (SARs) and molecular docking studies were also discussed in order to provide valuable insights for further structural optimizations. In summary, 5k turned out to be a promising NNRTI lead compound for further investigations of treatments for HIV-1 infections.