Small molecule RAF265 as an antiviral therapy acts against HSV-1 by regulating cytoskeleton rearrangement and cellular translation machinery.

Host-targeting antivirals (HTAs) have received increasing attention for their potential as broad-spectrum antivirals that pose relatively low risk of developing drug resistance. The repurposing of pharmaceutical drugs for use as antivirals is emerging as a cost- and time- efficient approach to developing HTAs for the treatment of a variety of viral infections. In this study, we used a virus titer method to screen 30 small molecules for antiviral activity against Herpes simplex virus-1 (HSV-1). We found that the small molecule RAF265, an anticancer drug that has been shown to be a potent inhibitor of B-RAF V600E, reduced viral loads of HSV-1 by 4 orders of magnitude in Vero cells and reduced virus proliferation in vivo. RAF265 mediated cytoskeleton rearrangement and targeted the host cell's translation machinery, which suggests that the antiviral activity of RAF265 may be attributed to a dual inhibition strategy. This study offers a starting point for further advances toward clinical development of antivirals against HSV-1.

Assembly-Induced Strong Circularly Polarized Luminescence of Spirocyclic Chiral Silver(I) Clusters.

Spirocyclic Ag9 clusters, as a new form of intrinsically chiral metal clusters, were constructed through vertex-sharing of two in-situ-generated heteroaryl diide-centered metal rings. Such core-peripheral type clusters exhibit versatile photoluminescent and chiroptical behavior under different aggregation conditions. In contrast to a ligand-based fluorescence emission in a diluted solution of the clusters, a solvent polarity-caused assembly gives rise to new cluster-based phosphorous luminescence owing to radiative mode switching and aggregation-induced emission. Assembly of cluster enantiomers leads to micrometer-long helical nanofibers, whose handedness is determined by absolute configuration of individual spirocyclic clusters. Benefiting from exciton couplings of helical arrangements of chelating ligands at molecular and microscopic levels, the assembled film of cluster enantiomers exhibits circularly polarized luminescence with a high anisotropy factor (0.16).

Recent advances in the NEK7-licensed NLRP3 inflammasome activation: Mechanisms, role in diseases and related inhibitors.

The nucleotide-binding oligomerization domain (NOD)-like receptor containing pyrin domain 3 (NLRP3) inflammasome is a high-molecular-weight complex mediated by the activation of pattern-recognition receptors (PRRs) seed in innate immunity. Once NLRP3 is activated, the following recruitment of the adapter apoptosis-associated speck-like protein containing a caspase recruitment domain (CARD) (ASC) and procaspase-1 would be initiated. Cleavage of procaspase-1 into active caspase-1 then leads to the maturation of the precursor forms of interleukin (IL)-1ß and IL-18 into biologically active IL-1ß and IL-18. The activation of NLRP3 inflammasome is thought to be tightly associated with a regulator never in mitosis A (NIMA)-related kinase 7 (NEK7), apart from other signaling events such as K+ efflux and reactive oxygen species (ROS). Plus, the NLRP3 inflammasome has been linked to various metabolic disorders, chronic inflammation and other diseases. In this review, we firstly describe the cellular/molecular mechanisms of the NEK7-licensed NLRP3 inflammasome activation. Then we detail the potential inhibitors that can selectively and effectively modulate either the NEK7-NLRP3 complex itself or the related molecular/cellular events. Finally, we describe some inhibitors as promising therapeutic strategies for diverse diseases driven by NLRP3 inflammasome.

Three kinds of treatment with Homoharringtonine, Hydroxychloroquine or shRNA and their combination against coronavirus PEDV in vitro.

BACKGROUND: Porcine epidemic diarrhea virus (PEDV) of the family Coronaviridae has caused substantial economic losses in the swine husbandry industry. There's currently no specific drug available for treatment of coronaviruses or PEDV. METHOD: In the current study, we use coronavirus PEDV as a model to study antiviral agents. Briefly, a fusion inhibitor tHR2, recombinant lentivirus-delivered shRNAs targeted to conserved M and N sequences, homoharringtonine (HHT), and hydroxychloroquine (HCQ) were surveyed for their antiviral effects. RESULTS: Treatment with HCQ at 50 µM and HHT at 150 nM reduced virus titer in TCID50 by 30 and 3.5 fold respectively, and the combination reduced virus titer in TCID50 by 200 fold. CONCLUSION: Our report demonstrates that the combination of HHT and HCQ exhibited higher antiviral activity than either HHT or HCQ exhibited. The information may contribute to the development of antiviral strategies effective in controlling PEDV infection.

Estrogen Promotes Hepatic Synthesis of Long-Chain Polyunsaturated Fatty Acids by Regulating ELOVL5 at Post-Transcriptional Level in Laying Hens.

The very long chain fatty acid elongase (ELOVL) plays an important role in the synthesis of long-chain polyunsaturated fatty acids (LCPUFA). Previous studies suggest that chicken could be an alternate source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In this study, we detected that ELOVL5, which plays a key role in the biosynthesis of omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFA), was highly expressed in the liver of laying hens and increased rapidly after sexual maturity. Bioinformatic analysis revealed ELOVL fatty acid elongase 5 (ELOVL5) gene as a putative target of miR-218-5p, miR-19a-3p, miR-19b-3p, miR-30a-5p, miR-30b-5p, and miR-30e-5p. We demonstrated estrogen downregulated microRNA (miRNA), and that ELOVL5 is a direct target of miR-218-5p, which was located in intron 14 of the Slit guidance ligand 2 (SLIT2) gene and co-expressed with the host gene. Overall, estrogen enhanced hepatic synthesis of LCPUFA by functioning as a negative regulator of miRNA thereby augmenting the expression of these miRNA target genes, especially ELOVL5, which plays a key role in the biosynthesis of n-3 and n-6 LCPUFA. This study provides a novel model for the use of estrogen in the poultry industry as an inducer of ELOVL5 expression to enhance hepatic n-3 and n-6 LCPUFA synthesis at the post-transcriptional level.

Association between sleep quality and cardiovascular damage in pre-dialysis patients with chronic kidney disease.

BACKGROUND: Poor sleep quality, a novel risk factor of cardiovascular diseases (CVD), is highly prevalent in patients with chronic kidney disease (CKD). The association between poor sleep quality and cardiovascular damage in patients with CKD is unclear. This study is aimed to assess the prevalence and related risk factors of sleep disturbance and determine the relationship between sleep quality and cardiovascular damage in Chinese patients with pre-dialysis CKD. METHODS: A total of 427 pre-dialysis CKD patients (mean age = 39 ± 15 years, 260 male/167 female) were recruited in this study. The demographics and clinical correlates were collected. The sleep quality was measured by the Pittsburgh Sleep Quality Index (PSQI), whereas the cardiovascular damage indicators (the Early/late diastolic peak flow velocity (E/A) ratio and left ventricular mass index (LVMI)) were determined by an echocardiographic examination. RESULTS: Of the CKD patients, 77.8% were poor sleepers as defined by a PSQI score > 5. Median estimated glomerular filtration rate (eGFR) was 69.4(15.8-110.9) ml/min/1.73 m(2). Logistic regression analysis revealed that left ventricular hypertrophy (LVH) was independently associated with the PSQI score (OR = 1.092, 95% CI = 1.011-1.179, p = 0.025), after adjustment for age, sex and clinical systolic blood pressure, diastolic blood pressure, Phosphate, Intact parathyroid hormone (iPTH), Hemoglobin and eGFR. The linear regression analysis showed that the E/A ratios were independently associated with the PSQI score (ß = -0.115, P = 0.028) after adjustment for a series of potential confounding factors. CONCLUSIONS: Poor sleep quality, which is commonly found in pre-dialysis CKD patients, is an independent factor associated with cardiovascular damage in CKD patients. Our finding implies that the association between poor sleep and CVD might be mediated by cardiac remodeling.

[Whole Exome Sequencing Reveals Gene Mutation Characteristics of Primary Central Nervous System Lymphoma].

OBJECTIVE: To investigate gene mutation characteristics of primary central nervous system lymphoma (PCNSL) through whole exome sequencing (WES) to 18 patients with PCNSL. METHODS: Tumor tissues from 18 patients with diffuse large B-cell lymphoma who were diagnosed with PCNSL in Department of Hematology, Lanzhou University Second Hospital from September 2018 to December 2020 and had normal immune function, no history of HIV or immunosuppressant therapy were collected. High-throughput-based WES was performed on the tumor tissues, with an average sequencing depth of >100×. After data processing and bioinformatics analysis of sequencing results, the mutation maps and mutation characteristics of 18 PCNSL patients were obtained. RESULTS: Obvious somatic mutations were detected in all 18 patients. The median number of somatic mutations was 321. Missense mutations were most prominent (accounting for about 90%), and the mutation type was dominated by C>T (50.2%), reflecting the age-related mutation pattern. Among the top 15 frequently mutated genes, PSD3, DUSP5, MAGEB16, TELO2, FMO2, TRMT13, AOC1, PIGZ, SVEP1, IP6K3, and TIAM1 were the driver genes. The enrichment results of driver gene pathways showed that RTK-RAS, Wnt, NOTCH, Hippo and Cell-Cycle pathways were significantly enriched. The tumor mutation burden was between 3.558 48/Mb and 8.780 89/Mb, and the average was 4.953 32/Mb, which was significantly higher than other cancer research cohorts in the TCGA database. CONCLUSIONS: PCNSL occurs somatic missense mutations frequently, mainly point mutations, and the mutation type is mainly C>T. The driver genes are mainly involved in RTK-RAS, Wnt, NOTCH and Hippo pathways, indicating that the above pathways may be related to the pathogenesis of PCNSL. PCNSL has a significantly high tumor mutation burden, which may explain the efficacy of PD-1 inhibitors in PCNSL.

[Clinical Features and Prognostic of Patients with Primary Central Nervous System Lymphoma].

OBJECTIVE: To explore the clinical features and prognosis of patients with primary central nervous system lymphoma（PCNSL）. METHODS: A retrospective analysis was performed on the relationship between clinical features, treatment regimen and prognosis in 46 newly diagnosed patients with primary central nervous system lymphoma who were diagnosed and treated in The Second Hospital of Lanzhou University from January 2015 to September 2022. Fisher's exact probability method was used to analyze the differences in clinical data of different subgroups. Kaplan-Meier survival curve was used to analyze the overall survival rate and progression-free survival rate of patients with different treatments, and the factors influencing survival were analyzed. RESULTS: Among 46 patients with PCNSL, which pathological type were diffuse large B-cell lymphoma（DLBCL）. There were 26(56.5%) cases of male and 20(43.5%) of female, with a median age of 54(17-71) years. In Hans subtypes, 14 cases (30.4%) of GCB subtype, 32 cases (69.6%) of non-GCB subtype. 32 cases (69.6%) of Ki-67≥80%. Among 36 patients who completed at least 2 cycles of treatment with follow-up data, the efficacy evaluation was as follows: overall response rate(ORR) was 63.9%, complete response(CR) rate was 47.2%, 17 cases of CR, 6 cases of PR. The 1-year progression-free survival rate and 1-year overall survival rate was 73.6% and 84.9%, respectively. The 2-year progression-free survival rate and 2-year overall survival rate was 52.2% and 68.9%, respectively. The ORR and CR rate of 17 patients treated with RMT regimen was 76.5% and 52.9% (9 cases CR and 4 cases PR), respectively. Univariate analysis of 3 groups of patients treated with RMT regimen, RM-BTKi regimen, and RM-TT regimen as first-line treament showed that deep brain infiltration was associated with adverse PFS(P =0.032), and treatment regimen was associated with adverse OS in PCNSL patients（P =0.025）. CONCLUSION: Different treatment modalities were independent prognosis predictors for OS, the deep brain infiltration of PCNSL is a poor predictive factor for PFS. Patients with relapse/refractory (R/R) PCNSL have a longer overall survival time because to the novel medication BTKi. They have strong toleration and therapeutic potential as a first-line therapy for high-risk patients.

Serum immunoglobulin A/C3 ratio predicts progression of immunoglobulin A nephropathy.

AIM: The serum immunoglobulin A (IgA)/C3 ratio has been shown to be a good predictor of histological lesions and prognosis for patients with IgA nephropathy (IgAN) in Japanese. But its validity in the Chinese population is unclear. We sought to explore the long-term outcomes of IgAN, its clinical and histopathological predictors in Chinese patients. In particular, the role of serum IgA/C3 ratio in the course of IgAN was addressed. METHODS: A total of 217 biopsy-diagnosed IgAN patients were recruited into this prospective cohort with a mean follow-up of 36 months (25-75th percentile, 27-48). Sociodemographics, serum IgA/C3 level, other clinical examinations and Lee's histological grade were measured. The patients with a decline of estimated glomerular filtration rate (eGFR) > 50% or developing end-stage renal disease (ESRD) were defined as progression. RESULTS: A total of 21 patients was found to progress (9.7%). In multivariate analysis, renal end point of IgAN was significantly predicted by proteinuria ≥1 g/day (relative risk (RR) = 2.65, 95% confidence interval (CI) 1.01-7.68), hypertension (RR = 3.15, 95% CI 1.07-9.29), higher Lee's histological grade (RR = 4.67, 95% CI 1.43-15.25) and serum IgA/C3 ratio ≥ 3.32 (RR = 4.31, 95% CI 1.33-13.96). CONCLUSION: A proportion of patients with IgAN developed end stage renal disease in a Chinese group. In addition to some traditional risk factors, we also confirmed that IgA/C3 ratio is a useful predictor of poor outcomes of IgAN in Chinese patients.

The ambulatory arterial stiffness index and target-organ damage in Chinese patients with chronic kidney disease.

BACKGROUND: The ambulatory arterial stiffness index (AASI) can be used to predict cardiovascular morbidity and mortality in hypertensive patients. However, data on AASI in Chinese patients with chronic kidney disease (CKD) is not available. METHODS: This cross-sectional study enrolled 583 CKD patients. Univariate and multivariate analyses were used to evaluate the relationship between AASI and renal function and parameters of cardiovascular injury. RESULTS: Patients with a higher AASI had a higher systolic blood pressure, a lower estimated glomerular filtration rate (eGFR), a higher serum cystatin C, a higher left ventricular mass index (LVMI) and carotid intima-media thickness (cIMT). Univariate analyses showed that AASI was positively correlated with serum cystatin C (r=0.296, P < 0.001), serum creatinine (r=0.182, P < 0.001), and LVMI (r = 0.205, P < 0.001) and negatively correlated with the eGFR (r = -0.200, P < 0.001). Multivariate analyses revealed that serum cystatin C, eGFR, serum creatinine and LVMI were independently correlated with AASI. CONCLUSIONS: These data suggest that AASI was closely correlated with renal function and parameters of cardiovascular injury in Chinese CKD patients. Good quality, long-term, large longitudinal trials to validate the role of AASI in clinical practice for Chinese CKD patients.

Proteomic screening identifies RPLp2 as a specific regulator for the translation of coronavirus.

Viral mRNA of coronavirus translates in an eIF4E-dependent manner, and the phosphorylation of eIF4E can modulate this process, but the role of p-eIF4E in coronavirus infection is not yet entirely evident. p-eIF4E favors the translation of selected mRNAs, specifically the mRNAs that encode proteins associated with cell proliferation, inflammation, the extracellular matrix, and tumor formation and metastasis. In the present work, two rounds of TMT relative quantitative proteomics were used to screen 77 cellular factors that are upregulated upon infection by coronavirus PEDV and are potentially susceptible to a high level of p-eIF4E. PEDV infection increased the translation level of ribosomal protein lateral stalk subunit RPLp2 (but not subunit RPLp0/1) in a p-eIF4E-dependent manner. The bicistronic dual-reporter assay and polysome profile showed that RPLp2 is essential for translating the viral mRNA of PEDV. RNA binding protein and immunoprecipitation assay showed that RPLp2 interacted with PEDV 5'UTR via association with eIF4E. Moreover, the cap pull-down assay showed that the viral nucleocapsid protein is recruited in m7GTP-precipitated complexes with the assistance of RPLp2. The heterogeneous ribosomes, which are different in composition, regulate the selective translation of specific mRNAs. Our study proves that viral mRNA and protein utilize translation factors and heterogeneous ribosomes for preferential translation initiation. This previously uncharacterized process may be involved in the selective translation of coronavirus.

Mesangial medium from IgA nephropathy patients induces podocyte epithelial-to-mesenchymal transition through activation of the phosphatidyl inositol-3-kinase/Akt signaling pathway.

BACKGROUND: Podocyte injury plays an important role in glomerulosclerosis in IgA nephropathy (IgAN). Eepithelial-to-mesenchymal transition (EMT) caused by different factors is the main reason for podocyte damage. This study hypothesized that conditioned mesangial medium may induced EMT process of podocytes and thereby lead to glomerular injury or sclerosis. MATERIALS AND METHODS: Podocytes were incubated in medium from mesangial cells incubated with aggregated IgA1(aIgA1) isolated from IgAN patients. Wortmannin were used to inhibit phosphatidylinositol-3-kinase (PI3-K) in podocytes. RESULTS: Western blot analysis, real-time PCR and confocal fluorescent microscopy demonstrated that reduced expression of P-Cadherin, Zonula occludens-1 (ZO-1) and podocin, increased expression of fibroblast -specific protein (FSP-1), α-smooth muscle action(α-SMA) and desmin in podocytes exposed to medium from mesangial cells incubated with aIgA1 isolated from IgAN patients compared with podocytes cultured in RPMI 1640 medium containing 0.5% fetal bovine serum ( FBS) (p<0.05). Mesangial medium resulted in a greater albumin influx across the podocyte monolayer (p<0.05). Phosphorylation of Akt increased with this medium, as indicated by an increase in the p-Akt/Akt ratio. Treatment with wortmannin partly restored the changes in epithelial and mesenchymal markers and albumin influx. IgAN patients with massive proteinuria showed remarkable α-SMA and FSP-1 expression in podocytes. CONCLUSION: Our findings indicated that mesangial medium from cells incubated with aIgA1 isolated from IgAN patients induced EMT in podocytes and the PI3-K/ Akt-signaling pathway was involved in the process.

Pyridine dicarbanion-bonded Ag13 organometallic nanoclusters: synthesis and on-surface oxidative coupling reaction.

Highly reactive organometallic nanoclusters in situ generated in metal-catalyzed reactions are pivotal in the comprehension of catalytic mechanisms. Herein, we develop a two-step synthetic method to achieve three unprecedented aryl dicarbanion-bonded Ag13 nanoclusters by using protective macrocyclic ligands. Firstly, various aryl dicarbanion-Ag4 cluster intermediates are acquired via a silver-mediated annulation reaction within a macrocyclic ligand. These Ag4 cluster precursors are released from the surrounding macrocycle by protonation, and further undergo an inter-cluster coupling to generate bipyridine products and low-valence silver atoms. The remaining resurgent diide-Ag4 clusters assemble with low-valence silver atoms to yield a series of organometallic Ag13 nanoclusters. These Ag13 nanoclusters feature a unique open-shell electronic structure as well as a chiral cluster architecture due to the asymmetric arrangements of surrounding aryl dianion ligands. Furthermore, the pyridyl diide ligands on the surface of the nanocluster further experience an intra-cluster oxidative coupling to produce bipyridine coupling products and large nanoparticles. The coupling reaction-driven cluster-to-cluster transformation is comprehensively tracked by high resolution mass spectroscopy. This work is not only reminiscent of the detailed evolution of cluster species upon the occurrence of coupling reactions, but also reproduces novel inter- and intra-cluster coupling steps at different reaction stages.

Small-Molecule RAF265 as an Antiviral Therapy Acts against PEDV Infection.

Porcine epidemic diarrhea virus (PEDV), a member of the family Coronaviridae, causes acute diarrhea, vomiting, dehydration, and high mortality in newborn piglets, and has caused significant economic losses in the pig industry. There are currently no specific drugs available to treat PEDV. Viruses depend exclusively on the cellular machinery to ensure an efficient replication cycle. In the present study, we found that small-molecule RAF265, an anticancer drug that has been shown to be a potent inhibitor of RAF, reduced viral loads of PEDV by 4 orders of magnitude in Vero cells, and protected piglets from virus challenge. RAF265 reduced PEDV production by mediating cytoskeleton arrangement and targeting the host cell's translation machinery. Treatment with RAF265 inhibited viral entry of PEDV S-glycoprotein pseudotyped viral vector particle (PEDV-pp), at half maximal effective concentrations (EC50) of 79.1 nM. RAF265 also presented potent inhibitory activity against viral infection by SARS-CoV-2-pp and SARS-CoV-pp. The present work may provide a starting point for further progress toward the development of antiviral strategies effective against coronavirus PEDV.

Target Fishing Reveals a Novel Mechanism of 1,2,4-Oxadiazole Derivatives Targeting Rpn6, a Subunit of 26S Proteasome.

1,2,4-Oxadiazole derivatives, a class of Nrf2-ARE activators, exert an extensive therapeutic effect on inflammation, cancer, neurodegeneration, and microbial infection. Among these analogues, DDO-7263 is the most potent Nrf2 activator and used as the core structure for bioactive probes to explore the precise mechanism. In this work, we obtained compound 7, a mimic of DDO-7263, and biotin-labeled and fluorescein-based probes, which exhibited homologous biological activities to DDO-7263, including activating Nrf2 and its downstream target genes, anti-oxidative stress, and anti-inflammatory effects. Affinity chromatography and mass analysis techniques revealed Rpn6 as the potential target protein regulating the Nrf2 signaling pathway. In vitro affinity experiments further confirmed that DDO-7263 upregulated Nrf2 through binding to Rpn6 to block the assembly of 26S proteasome and the subsequent degradation of ubiquitinated Nrf2. These results indicated that Rpn6 is a promising candidate target to activate the Nrf2 pathway for protecting cells and tissues from oxidative, electrophilic, and exogenous microbial stimulation.

Development of Novel Tetrahydroquinoline Inhibitors of NLRP3 Inflammasome for Potential Treatment of DSS-Induced Mouse Colitis.

The NLRP3 inflammasome is a critical component of innate immunity, which defends internal and external threats. However, inappropriate activation of the NLRP3 inflammasome induces various human diseases. In this study, we discovered and synthesized a series of tetrahydroquinoline inhibitors of NLRP3 inflammasome. Among these analogues, compound 6 exhibited optimal NLRP3 inhibitory activity. In vitro studies indicated that compound 6 directly bound to the NACHT domain of NLRP3 but not to protein pyrin domain (PYD) or LRR domain, inhibited NLRP3 ATPase activity, and blocked ASC oligomerization, thereby inhibiting NLRP3 inflammasome assembly and activation. Compound 6 specifically inhibited the NLRP3 inflammasome activation, but had no effect on the activation of NLRC4 or AIM2 inflammasomes. Furthermore, in the dextran sulfate sodium (DSS)-induced colitis mouse model, compound 6 exhibited significant anti-inflammatory activity through inhibiting NLRP3 inflammasome in vivo. Therefore, our study provides a potent NLRP3 inflammasome inhibitor, which deserves further structural optimization as a novel therapeutic candidate for NLRP3-driven diseases.

Ultrasound of urinary system and urinary screening in 14 256 asymptomatic children in China.

AIM: The aim of this study is to assess the characteristics of urinary system diseases and the role of the ultrasound screening and urinalysis screening for chronic kidney disease (CKD) in asymptomatic children in China. METHODS: Between September 2008 and November 2008, 14 256 children excluding those with obvious symptoms and signs were enrolled in our study. All the subjects accepted ultrasound and urinary screening. A case-control study was performed to evaluate the relative risk of having stones in those children exposed to melamine formula. RESULTS: Of the enrolled children, 6.10% (869 of 14 256) showed abnormalities, of which 409 (2.87%) were established by ultrasound, 572 (4.01%) by urinalysis and 112 (0.79%) by both ultrasound screening and urinalysis. The abnormalities included congenital anomalies of kidney and urinary tract, urinary stones and/or hydronephrosis, leucocyturia and haematuria and/or proteinuria. Children exposed to melamine formula were 5.17 times as likely to have kidney stones as children exposed to no-melamine formula (95% confidence interval, 3.28-8.14; P < 0.001); the probability of kidney stones in melamine-fed infants were 6.28 times as likely as those no melamine-fed (95% confidence interval, 3.71-10.65; P < 0.001). CONCLUSION: Ultrasonography and urinalysis could complement each other and play important roles in the early diagnosis of anomalies of the urinary system, but urinalysis is a more cost-effective screening tool for CKD in children in China. Exposure to melamine-contaminated formula associated with urinary stones, especially in infants, was significantly higher than the control group.

Selective apoptosis-inducing activity of synthetic hydrocarbon-stapled SOS1 helix with d-amino acids in H358 cancer cells expressing KRASG12C.

Lung cancer is one of the most malignant tumors with the highest morbidity and mortality. Most of them are non-small cell lung cancer (NSCLC). KRASG12C gene mutation is an important driving factor for NSCLC. However, the development of high-affinity inhibitors targeting KRASG12C mutants remains a daunting challenge. Here, we report the design and development of a series of hydrocarbon-stapled peptides containing d-amino acids to mimic the alpha helix of SOS1. D-hydrocarbon-stapled peptides maintain good alpha helix structure and bind to KRASG12C with high affinity. Subsequent anti-proliferation experiments indicated that D-hydrocarbon-stapled peptide 5 inhibited the proliferation of NSCLC H358 cells carrying KRASG12C. However, it showed no significant anti-proliferative effect on KRASG12S-positive A549 cells, suggesting that peptide 5 selectively inhibits KRASG12C-driven tumor cells. D-hydrocarbon-stapled peptide 5 could also cause the cell cycle of H358 cells to arrest in the G2/M phase and induce apoptosis. No significant cell arrest and apoptosis were observed in A549 cells treated by peptide 5. In summary, the introduction of d-amino acids could improve the affinity and cell selectivity of hydrocarbon peptides. We hope that peptides containing D-form amino acids can provide strategies for further optimization of the KRASG12C/SOS1 inhibitor.

Repurposing host-based therapeutics to control coronavirus and influenza virus.

The development of highly effective antiviral agents has been a major objective in virology and pharmaceutics. Drug repositioning has emerged as a cost-effective and time-efficient alternative approach to traditional drug discovery and development. This new shift focuses on the repurposing of clinically approved drugs and promising preclinical drug candidates for the therapeutic development of host-based antiviral agents to control diseases caused by coronavirus and influenza virus. Host-based antiviral agents target host cellular machineries essential for viral infections or innate immune responses to interfere with viral pathogenesis. This review discusses current knowledge, prospective applications and challenges in the repurposing of clinically approved and preclinically studied drugs for newly indicated antiviral therapeutics.

5-(3,4-Difluorophenyl)-3-(6-methylpyridin-3-yl)-1,2,4-oxadiazole (DDO-7263), a novel Nrf2 activator targeting brain tissue, protects against MPTP-induced subacute Parkinson's disease in mice by inhibiting the NLRP3 inflammasome and protects PC12 cells against oxidative stress.

Parkinson's disease (PD) is the second most common aging-related neurodegenerative disease worldwide. Oxidative stress and neuroinflammation are critical events in the degeneration of dopaminergic neurons in PD. In this study, we found that DDO-7263, a novel Nrf2-ARE activator reported by us, has ideal therapeutic effects on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease in mice. DDO-7263 improved the behavioral abnormalities induced by MPTP in mice, significantly attenuated chemically induced dopaminergic neuron loss of tyrosine hydroxylase (TH) in the substantia nigra (SN) and striatum of the mouse brain and inhibited the secretion of inflammatory factors. In addition, DDO-7263 protected PC12 neurons from H2O2-induced oxidative damage. The neuroprotective effects of DDO-7263 were confirmed both in vitro and in vivo models. Further studies showed that the neuroprotective effect of DDO-7263 was mediated by the activation of Nrf2-ARE signaling pathway and the inhibition of NLRP3 inflammasome activation. DDO-7263 induced NLRP3 inflammasome inhibition is dependent on Nrf2 activation. This conclusion was also verified in THP-1-derived macrophages (THP-Ms). DDO-7263 significantly inhibited NLRP3 activation, cleaved caspase-1 production and IL-1ß protein expression in ATP-LPS-exposed THP-Ms cells. The pharmacokinetic parameters and tissue distribution results indicated that DDO-7263 has a brain tissue targeting function. All these lines of evidence show that DDO-7263 has ideal therapeutic effects on neurodegenerative diseases such as PD.