Discovery Small-Molecule p300 Inhibitors Derived from a Newly Developed Indazolone-Focused DNA-Encoded Library.

The DNA-encoded library (DEL) is a robust tool for chemical biology and drug discovery. In this study, we developed a DNA-compatible light-promoted reaction that is highly efficient and plate-compatible for DEL construction based on the formation of the indazolone scaffold. Employing this high-efficiency approach, we constructed a DEL featuring an indazolone core, which enabled the identification of a novel series of ligands specifically targeting E1A-binding protein (p300) after DEL selection. Taken together, our findings underscore the feasibility of light-promoted reactions in DEL synthesis and unveil promising avenues for developing p300-targeting inhibitors.

Discovery and Optimization of WDR5 Inhibitors via Cascade Deoxyribonucleic Acid-Encoded Library Selection Approach.

The DNA-encoded library (DEL) is a powerful hit generation tool for chemical biology and drug discovery; however, the optimization of DEL hits remained a daunting challenge for the medicinal chemistry community. In this study, hit compounds targeting the WIN binding domain of WDR5 were discovered by the initial three-cycle linear DEL selection, and their potency was further enhanced by a cascade DEL selection from the focused DEL designed based on the original first run DEL hits. As expected, these new compounds from the second run of focused DEL were more potent WDR5 inhibitors in the protein binding assay confirmed by the off-DNA synthesis. Interestingly, selected inhibitors exhibited good antiproliferative activity in two human acute leukemia cell lines. Taken together, this new cascade DEL selection strategy may have tremendous potential for finding high-affinity leads against WDR5 and provide opportunities to explore and optimize inhibitors for other targets.

Rapidly progressive interstitial lung disease combined with pneumocystis jiroveci pneumonia in a patient with single anti-TIF-1γ antibody positive dermatomyositis in the context of an underlying tumor.

BACKGROUND: Interstitial lung disease (ILD) is a frequently observed comorbidity in autoimmune diseases such as dermatomyositis/polymyositis (DM/PM), and it is significantly associated with specific autoantibody types. One unique antibody type is the anti-transcription intermediate factor-1γ antibody (anti-TIF-1γ Ab), which has a positive rate of only 7%. It is often found in combination with malignancy and rarely with ILD, particularly rapidly progressive ILD (RPILD). In some cases, the presence of ILD in individuals with DM may indicate a paraneoplastic syndrome. Pneumocystis jiroveci pneumonia (PJP) typically occurs due to intensive immunosuppressive therapy, human immunodeficiency virus (HIV) infection, or malignancy, and rarely as an isolated condition. CASE PRESENTATION: A 52-year-old man with a history of rapid weight loss but non-HIV infected and not immunosuppressed who presented with fever, cough, dyspnea, weakness of the extremities, characteristic rash and mechanic's hand. Pathogenic tests suggested PJP, laboratory tests suggested a single anti-TIF-1γ Ab positive DM, imaging suggested ILD, and pathology revealed no malignancy. RPILD and acute respiratory distress syndrome (ARDS) developed after anti-infection and steroid hormone therapy. After mechanical support therapy such as Extracorporeal Membrane Oxygenation (ECMO), the patient developed late-onset cytomegalovirus pneumonia (CMVP), complicated bacterial infection, and ultimately death. Additionally, we discuss the potential causes of rapid weight loss, the mechanisms by which anti-TIF-1γ Ab may lead to ILD, and the possible connection between anti-TIF-1γ Ab positivity, rapid weight loss, immune abnormalities, and opportunistic infections. CONCLUSIONS: This case emphasizes the importance of early recognition of malignant tumors and pulmonary lesions, assessment of the body's immune status, prompt initiation of immunosuppressive treatment, and prevention of opportunistic infections in individuals with single anti-TIF-1γ Ab positive DM presenting with rapid weight loss.

Abscisic Acid May Play a Critical Role in the Moderating Effect of Epichloë Endophyte on Achnatherum inebrians under Drought Stress.

Water scarcity is a major constraint that adversely affects plant development and growth. Abscisic acid (ABA) is a plant stress hormone that is rapidly synthesized and can induce stomatal closure to conserve water, thereby alleviating the drought stress of plants. The Epichloë endophyte enhances the drought tolerance of Achnatherum inebrians (drunken horse grass, DHG). To better understand how the Epichloë endophyte enhances drought tolerance, DHG plants without (EF) and with (EI), an Epichloë endophyte, were grown under 20% and 60% soil water conditions (SWC), and the leaves of the three treatments of EF and EI plants were sprayed with ABA solution (1 mg/L); fluridone (FLU), the ABA biosynthesis inhibitor solution (1 mg/L); and distilled water, respectively. Four-weeks later, the results indicated that the exogenous ABA application promoted plant growth, stomatal conductance, and photosynthetic rate, while the opposite effect occurred with plants sprayed with FLU. The differences between EI and EF plants in tiller number, height, chlorophyll content, stomata conductance, and photosynthetic rate were highest when sprayed with ABA. Thus, it is concluded that ABA might be involved in the moderating effect of Epichloë endophytes on DHG plants exposed to drought by maintaining growth and improving photosynthetic efficiency.

Diversified strategy for the synthesis of DNA-encoded oxindole libraries.

DNA-encoded library technology (DELT) employs DNA as a barcode to track the sequence of chemical reactions and enables the design and synthesis of libraries with billions of small molecules through combinatorial expansion. This powerful technology platform has been successfully demonstrated for hit identification and target validation for many types of diseases. As a highly integrated technology platform, DEL is capable of accelerating the translation of synthetic chemistry by using on-DNA compatible reactions or off-DNA scaffold synthesis. Herein, we report the development of a series of novel on-DNA transformations based on oxindole scaffolds for the design and synthesis of diversity-oriented DNA-encoded libraries for screening. Specifically, we have developed 1,3-dipolar cyclizations, cyclopropanations, ring-opening of reactions of aziridines and Claisen-Schmidt condensations to construct diverse oxindole derivatives. The majority of these transformations enable a diversity-oriented synthesis of DNA-encoded oxindole libraries which have been used in the successful hit identification for three protein targets. We have demonstrated that a diversified strategy for DEL synthesis could accelerate the application of synthetic chemistry for drug discovery.

Streamlined construction of peptide macrocycles via palladium-catalyzed intramolecular S-arylation in solution and on DNA.

A highly efficient and versatile method for construction of peptide macrocycles via palladium-catalyzed intramolecular S-arylation of alkyl and aryl thiols with aryl iodides under mild conditions is developed. The method exhibits a broad substrate scope for thiols, aryl iodides and amino acid units. Peptide macrocycles of a wide range of size and composition can be readily assembled in high yield from various easily accessible building blocks. This method has been successfully employed to prepare an 8-million-membered tetrameric cyclic peptide DNA-encoded library (DEL). Preliminary screening of the DEL library against protein p300 identified compounds with single digit micromolar inhibition activity.

Isorhynchophylline enhances Nrf2 and inhibits MAPK pathway in cardiac hypertrophy.

Isorhynchophylline (IRN) is one of the major tetracyclic oxindole alkaloids found in Uncaria rhynchophylla. Studies have found that IRN has diverse biological activities including antioxidant, anti-apoptosis, and neuroprotection. However, little is known about the effect of IRN on the development of cardiac hypertrophy. In this study, we investigated the change of the cell surface area and nascent protein synthesis of cultured H9c2 cardiomyocytes on exposure to phenylephrine (PE) plus IRN, and thus confirmed that IRN ameliorated cardiomyocyte hypertrophy induced by PE in vitro. Meanwhile, it turns out that IRN is also effective in neonatal rat ventricular myocytes (NRVMs) stimulated with angiotensin II (AngII). We also showed that IRN prevented cardiac dysfunction in mice with pressure overload due to transverse aortic constriction (TAC) and attenuated cardiac hypertrophy and fibrosis. IRN treatment improved the cardiac function assessed by echocardiographic parameters fractional shortening (FS) as well as suppressed the cardiac hypertrophy phenotypes, such as the increasing of ventricular mass/body weight and myocyte cross-sectional area. RT-PCR analysis showed that IRN treatment also alleviated the expression of fetal genes of ANP, BNP, Myh7, and the correlated fibrosis genes including TGF-ß1, collagen I, collagen III, and CTGF in vivo. Meanwhile, IRN had anti-oxidative effects on cardiac remodeling with suppressed 4-HNE and MDA. Western blot analysis showed that the Nrf2 nuclear translocation and MAPK pathway were involved in the potential mechanisms of IRN on cardiac hypertrophy inhibition. The results of our study provide further evidence that IRN is a promising drug for the treatment of cardiac hypertrophy.

Novel KCNQ2 channel activators discovered using fluorescence-based and automated patch-clamp-based high-throughput screening techniques.

AIM: To establish an improved, high-throughput screening techniques for identifying novel KCNQ2 channel activators. METHODS: KCNQ2 channels were stably expressed in CHO cells (KCNQ2 cells). Thallium flux assay was used for primary screening, and 384-well automated patch-clamp IonWorks Barracuda was used for hit validation. Two validated activators were characterized using a conventional patch-clamp recording technique. RESULTS: From a collection of 80 000 compounds, the primary screening revealed a total of 565 compounds that potentiated the fluorescence signals in thallium flux assay by more than 150%. When the 565 hits were examined in IonWorks Barracuda, 38 compounds significantly enhanced the outward currents recorded in KCNQ2 cells, and were confirmed as KCNQ2 activators. In the conventional patch-clamp recordings, two validated activators ZG1732 and ZG2083 enhanced KCNQ2 currents with EC50 values of 1.04±0.18 µmol/L and 1.37±0.06 µmol/L, respectively. CONCLUSION: The combination of thallium flux assay and IonWorks Barracuda assay is an efficient high-throughput screening (HTS) route for discovering KCNQ2 activators.

The Differences in the Epidemiology and Predictors of Death between Candidemia Acquired in Intensive Care Units and Other Hospital Settings.

OBJECTIVE: The burden of candidemia is shifting from intensive care units (ICU) to non-ICU settings. This study aimed to define the differences in epidemiology and predictors of death between ICU-acquired candidemia (ICUAC) and non-ICUAC. METHODS: We conducted a retrospective study of 80 patients with ICUAC and 147 patients with non-IUCAC at five hospitals. RESULTS: The distribution of Candida species and resistance to antifungal agents did not differ between the ICUAC and non-ICUAC groups. ICUAC patients received more echinocandins and less triazoles, as well as more adequate antifungal therapy than non-ICUAC patients (all p<0.05). ICUAC patients had a significantly higher average acute physiology and chronic health evaluation (APACHE) II score (21.0±7.9 vs. 17.8±8.6; p<0.01), Sequential Organ Failure Assessment score (9.2±5.5 vs. 7.4±3.9; p<0.05) and day-90 mortality rate (52.5% vs. 36.7%; p<0.05) when compared to non-ICUAC patients. Using a multivariate logistic analysis, adequate antifungal therapy was found to be the only protective factor for death in both groups. Respiratory failure supported with invasive mechanical ventilation, renal failure supported with replacement therapy and an APACHE II score ≥20 were independent predictors of death in ICUAC patients, while age ≥60 years, concurrent bacteremia and APACHE II score ≥20 were independent predictors of death in non-ICUAC patients. CONCLUSION: The Candida species and antifungal resistance profiles in patients with ICUAC were similar to non-ICUAC patients, but led to worse outcomes. The protective and risk factors for death may therefore be relevant for the clinical management of patients with candidemia in ICU and non-ICU settings.

The epidemiology, antifungal use and risk factors of death in elderly patients with candidemia: a multicentre retrospective study.

BACKGROUND: The elderly patients affected by candidemia are growing in proportion to inpatients, but available data are limited. We aimed to determine the epidemiology, antifungal management and clinical risk factors of death in the elderly population with candidemia in China. METHODS: This retrospective study included 63 elderly (≥65 years) and 84 younger patients (16-60 years) at 4 tertiary hospitals. Multivariable logistic regression model was used to identify independent risk factors of death in elderly patients. RESULTS: The distribution of Candida species did not differ between elderly and younger patients (p >0.05). Resistance to fluconazole and voriconazole for non-Candida albicans species in elderly patients was approximately double that in younger patients. Host-related risk factors (e.g., underlying solid tumour, diabetes mellitus and chronic renal failure) and hospital-related factors (e.g., prior stay in an intensive care unit, mechanical ventilation, central vascular and urethral catheters placement) were identified more common in elderly patients. Elderly patients less often received triazoles and were less likely to receive antifungal therapies mostly because elderly or their guardians quit antifungal therapies. APACHE II scores and 30-day mortality were higher for elderly than younger patients (31.7% vs. 16.7%, p =0.032). For elderly patients, antifungal therapy administered before microbiological documentation was the only protective factor for death, whereas absence of antifungal therapies, receipt of mechanical ventilation and APACHE II score ≥20 were independent predictors of death. CONCLUSIONS: Elderly patients with candidemia had poor prognoses characterized by certain host and hospital-related risk factors and special pathogen resistance features. More awareness of the burden of this disease is required, and the absence of antifungal therapies should be avoided to improve the prognoses of elderly patients with this severe infection.

Antibiotics exposure, risk factors, and outcomes with Candida albicans and non-Candida albicans candidemia. Results from a multi-center study.

OBJECTIVE: To define the differences in antibiotics exposure, risk factors, and outcome in hospitalized patients with Candida albicans (C. albicans) and non-C. albicans candidemia. METHODS: This is a multi-center retrospective study of 132 patients with candidemia from 5 tertiary-care educational hospitals in Shandong, China conducted between January 2009 and June 2010. Fifty-six of 132 (42.4%) patients had candidemia due to C. albicans and 76/132 (57.6%) had non-C. albanians candidemia. RESULTS: Patients with non-C. albicans candidemia received anti-anaerobic agents more often (23.7% versus 8.9%; p=0.027) and beta-lactam/beta-lactamase inhibitors less often (34.2% versus 51.8%; p=0.043) than those with C. albicans candidemia. Independent risk factors of non-C. albicans candidemia were prior anti-anaerobic and antifungal therapies and central venous catheter placement. Overall, 30-day mortality was higher for patients with C. albicans than non-C. albicans candidemia (50% versus 31.6%; p=0.032). Multivariate logistic regression analysis revealed that C. albicans candidemia, advanced age, and concomitant bacteremia were associated with death due to candidemia. CONCLUSION: Patients who received anti-anaerobic or antifungal agents were likely to develop non-C. albicans candidemia. Candida albicans infection was associated with poorer prognosis. An awareness of these factors is needed to guide therapy and decrease the high mortality of candidemia.

The ethylene bis-dithiocarbamate fungicide Mancozeb activates voltage-gated KCNQ2 potassium channel.

Mancozeb (manganese/zinc ethylene bis-dithiocarbamate) is an organometallic fungicide that has been associated with human neurotoxicity and neurodegeneration. In a high-throughput screen for modulators of KCNQ2 channel, a fundamental player modulating neuronal excitability, Mancozeb, was found to significantly potentiate KCNQ2 activity. Mancozeb was validated electrophysiologically as a KCNQ2 activator with an EC50 value of 0.92±0.23µM. Further examination showed that manganese but not zinc ethylene bis-dithiocarbamate is the active component for the positive modulation effects. In addition, the compounds are effective when the metal ions are substituted by iron but lack potentiation activity when the metal ions are substituted by sodium, signifying the importance of the metal ion. However, the iron (Fe(3+)) alone, organic ligands alone or the mixture of iron with the organic ligand did not show any potentiation effect, suggesting as the active ingredient is a specific complex rather than two separate additive or synergistic components. Our study suggests that potentiation on KCNQ2 potassium channels might be the possible mechanism of Mancozeb toxicity in the nervous system.

[Use of the AKIN criteria to assess the incidence of acute renal injury, outcome and prognostic factors of ICU mortality in critically ill patients].

OBJECTIVE: To evaluate the value of the AKIN criteria of acute kidney injury (AKI) in the incidence and prognoses in critically ill patients, and to further identify risk factors associated with the prognoses of the critically ill patients. METHODS: We retrospectively studied 544 adult patients hospitalized for ≥24 h to a comprehensive ICU with 16 beds in teaching hospital from January 2008 to December 2009. Based on AKIN criteria, these patients were classified into four groups: NAKI (no AKI), AKII, AKIII, and AKIIII respectively. RESULTS: (1) Of the patients, 191 (35.5%) fulfilled the criteria for AKI (14.8% had AKI I 8.2% had AKI II and 11.9% had AKIIII). (2) Mortality in the ICU was much higher in patients with AKI than in patients with no AKI (48% vs 11%, OR 7.48, 95%CI 4.831-11.587, P<0.001). The mortality rate was 37% for AKII group, 51% for AKIII group and 60% for AKIIII group. (3) In multivariate analysis, each AKIN category was independently associated with ICU mortality. The other independent risk factors for ICU mortality included internal medical diseases, septic shock, pre-existing chronic illness, APACHEII score, the number of failed organs, mechanical ventilation and CRRT. CONCLUSIONS: The AKIN category closely relates to the prognoses in critically ill patients, even the mild degree of AKI with a much higher mortality rate than the patients without AKI. The AKIN criteria has some direction significance to the early detection and classification of AKI and to the prediction of clinical outcomes in critically ill patients.

On the assay of brachytherapy sources.

In many of brachytherapy procedures, a large amount of radioactive sources are used to deliver desired doses to the target volume. It is both the federal regulation recommendation (U.S. Nuclear Regulatory Commission, 10 CFR 35.432) and recommendations of the American Association of Physicists in Medicine (AAPM) [Kutcher et al., Med. Phys. 21, 581-618 (1994); Nath et al., Med. Phys. 24, 1557-1598 (1997)] that users independently verify the sources' strength. Though the reports of AAPM Task Group 40 [Kutcher et al., Med. Phys. 21, 581-618 (1994)] and 56 [Nath et al., Med. Phys. 24, 1557-1598 (1997)] have made specific recommendations on the assay of brachytherapy sources, the relevant statistical significance of the recommendations remain unanswered. In this study, statistical theories were used and a method was presented to quantify the assay process of brachytherapy sources and to evaluate the recommendations. The results showed that the quality of a source assay process was dependent on the measured source strength deviation and number of assayed sources. Its dependence on the total number of sources becomes statistically insignificant if the total number is large enough. It was concluded that the assay process can be determined by the obtained assay information, instead of a preset percentage of total sources. It was further found that the use of manufacturer's stated strength value may possibly lead to bigger uncertainty in source strength accuracy, unless the manufacturer's stated strength is the measured mean value of all the ordered sources.