Lipid parameters, adipose tissue distribution and prognosis prediction in chronic kidney Disease patients.

BACKGROUND: Lipid management in clinic is critical to the prevention and treatment of Chronic kidney disease (CKD), while the manifestations of lipid indicators vary in types and have flexible association with CKD prognosis. PURPOSE: Explore the associations between the widely used indicators of lipid metabolism and their distribution in clinic and CKD prognosis; provide a reference for lipid management and inform treatment decisions for patients with non-dialysis CKD stage 3-5. METHODS: This is a retrospective cohort study utilizing the Self-Management Program for Patients with Chronic Kidney Disease Cohort (SMP-CKD) database of 794 individuals with CKD stages 3-5. It covers demographic data, clinical diagnosis and medical history collection, laboratory results, circulating lipid profiles and lipid distribution assessments. Primary endpoint was defined as a composite outcome(the initiation of chronic dialysis or renal transplantation, sustained decline of 40% or more in estimated glomerular filtration rate (eGFR), doubled of serum creatinine (SCr) from the baseline, eGFR less than 5 mL/min/1.73m2, or all-cause mortality). Exposure variables were circulating lipid profiles and lipid distribution measurements. Association were assessed using Relative risks (RRs) (95% confidence intervals (CIs)) computed by multivariate Poisson models combined with least absolute shrinkage and selection operator (LASSO) regression according to categories of lipid manifestations. The best model was selected via akaike information criterion (AIC), area under curve (AUC), receiver operating characteristic curve (ROC) and net reclassification index (NRI). Subgroup analysis and sensitivity analysis were performed to assess the interaction effects and robustness.. RESULTS: 255 individuals reached the composite outcome. Median follow-up duration was 2.03 [1.06, 3.19] years. Median age was 58.8 [48.7, 67.2] years with a median eGFR of 33.7 [17.6, 47.8] ml/min/1.73 m2. Five dataset were built after multiple imputation and five category-based Possion models were constructed for each dataset. Model 5 across five datasets had the best fitness with smallest AIC and largest AUC. The pooled results of Model 5 showed that total cholesterol (TC) (RR (95%CI) (per mmol/L) :1.143[1.023,1.278], P = 0.018) and percentage of body fat (PBF) (RR (95%CI) (per percentage):0.976[0.961,0.992], P = 0.003) were significant factors of composite outcome. The results indicated that comprehensive consideration of lipid metabolism and fat distribution is more critical in the prediction of CKD prognosis.. CONCLUSION: Comprehensive consideration of lipid manifestations is optimal in predicting the prognosis of individuals with non-dialysis CKD stages 3-5.

Ultra-processed food consumption and the risk of incident chronic kidney disease: a systematic review and meta-analysis of cohort studies.

BACKGROUND: Recent individual studies have indicated that ultra-processed food (UPF) consumption may be associated with the incidence of chronic kidney disease (CKD). We conducted a systematic review and meta-analysis based on those longitudinal studies evaluating the relationship between UPF consumption and the risk of incident CKD, and synthesizing the results. METHOD: PubMed, Embase, The Cochrane Library, Web of Science, and Scopus were searched from inception through 22 March 2023. Any longitudinal studies evaluating the relationship between UPF consumption and the risk of incident CKD were included. Two researchers independently conducted the literature screening and data extraction. RR and its 95% CI were regarded as the effect size. The Newcastle-Ottawa Scale (NOS) was applied to assess the quality of the studies included, and the effect of UPF consumption on the risk of incident CKD was analyzed with STATA version 15.1. This study's protocol was registered in PROSPERO (CRD42023411951). RESULTS: Four cohort studies with a total of 219,132 participants were included after screening. The results of the meta-analysis suggested that the highest UPF intake was associated with an increased risk of incident CKD (RR = 1.25; 95% CI: 1.18-1.33). CONCLUSIONS: High-dose UPF intake was associated with an increased risk of incident CKD. However, the underlying mechanisms remain unknown. Thus, more standardized clinical studies and further exploration of the mechanisms are needed in the future.

Interaction of miR-200a-3p with YAP regulates cell proliferation and metastasis differentially in HPV-positive and HPV-negative cervical cancer cells.

BACKGROUND: Although evidence has revealed that miR-200a-3p is involved in the malignant progression of various tumors, the regulatory mechanism of miR-200a-3p in the development of cervical cancer (CC) cells with different HPV statuses remains unknown. The present study was to investigate the differential effects of either miR-200a-3p or YAP on tumorous cells' fate in vitro in HPV-negative and HPV-positive cervical cancer cell models, and to explore if the changes in proliferation, migration, and invasion of the CC cells with different HPV statuses could be attributed to the differential interactions between miR-200a-3p and YAP. METHODS: The colony formation assays, EDU assays and Transwell assays were performed for CC cell proliferation, migration and invasion capacities analysis. The prediction of downstream targets of miR-200a-3p was performed by bioinformatical databases. The dual-luciferase reporter assays were used to validate the binding sites of miR-200a-3p and YAP. The qRT-PCR assays were performed to quantify the mRNA expression of miR-200a-3p and YAP, and the protein levels of YAP were examined by Western blot analysis. RESULTS: The results demonstrated that miR-200a-3p overexpression suppressed proliferation, migration, and invasion of the HPV-negative C33A cells but promoted the growth and metastasis of HPV-positive CC cells, while YAP promoted the cell growth and metastasis not only in HPV-negative but also in the HPV-positive CC cells. The suppressive role of miR-200a-3p in C33A cells appeared to be mediated partially by direct interaction with YAP, and YAP might participate in miR-200a-3p-mediated cellular changes in CC cells differing from not only the presence or absence of HPV but even also the subtypes of HPV of CC cells. Meanwhile, we preliminarily revealed that the expression level of miR-200a-3p was significantly decreased in HPV-negative, but not in HPV16-positive cervical neoplasm mucus samples. CONCLUSION: miR-200a-3p-mediated functional changes of YAP exhibited regulatory effects on cells' fate differentially in HPV-negative and HPV-positive cervical cancer cells.

The impact of body mass index on clinicopathological features of nonalcoholic fatty liver disease in Taiwan.

BACKGROUND AND AIM: The aim of this study was to assess the impact of body mass index (BMI) on the clinical and histological characteristics of patients with nonalcoholic fatty liver disease (NAFLD). METHODS: Patients with clinically diagnosed NAFLD who received liver biopsy were retrospectively enrolled from 2007 to 2019. For comparison, all of the patients were divided into lean body mass (< 23 kg/m2 ), overweight (23-24.9 kg/m2 ), and obesity (BMI â‰§ 25 kg/m2 ). RESULTS: A total of 572 patients with histologically confirmed NAFLD, including 40 (6.99%) lean body mass, 54 (9.44%) overweight, and 478 (83.57%) obese patients, were recruited. Obese NAFLD patients had significantly higher grade of steatosis (grade 3: 29.92% vs 22.22% vs 12.5%, P < 0.0001) and hepatocyte ballooning (grade 2: 14.85% vs 12.96% vs 12.5%, P < 0.0001) than overweight and lean NAFLD patients. The prevalence of nonalcoholic steatohepatitis (NASH) was 22.5%, 25.93%, and 36.19% in lean, overweight, and obese NAFLD patients, respectively. Obesity was significantly associated with fibrosis severity (P = 0.03). The fibrosis index based on four factors (FIB-4) score can identify NAFLD patients without significant fibrosis or with cirrhosis. The areas under the receiver-operating characteristic curve of FIB-4 score to identify patients without significant fibrosis or with cirrhosis were 0.82 (95% confidence interval [CI]: 0.69-0.96) and 0.87 (95% CI: 0.76-0.99) in lean patients; 0.77 (95% CI: 0.61-0.93) and 0.81 (95% CI: 0.59-1.0) in overweight patients; and 0.77 (95% CI: 0.72-0.82) and 0.89 (95% CI: 0.85-0.92) in obese patients. CONCLUSIONS: The majority of NAFLD patients are obese, as defined by BMI. Obesity was significantly associated with NASH and hepatic fibrosis severity in patients with NAFLD.

Self-management program for patients with chronic kidney disease (SMP-CKD) in Southern China: protocol for an ambispective cohort study.

BACKGROUND: Chronic kidney disease (CKD) is a major global health problem. Short-term self-management has been considered to effect some renal and psychological endpoints. However, there are currently very few studies about self-management for CKD that a) have been scientifically designed by a theory-based framework and b) that evaluate the long-term effects and working mechanism. This study presents the rationale and design of a theory-based cohort study to explore how this self-management intervention works and its effectiveness on the Chinese CKD population. METHODS: In this ambispective intervention cohort study,1,200 patients with CKD stages 1-5 will be recruited from July 2015 to July 2024 in 3 branches of Guangdong Provincial Hospital of Chinese Medicine (GPHCM) in Guangdong province, China. The patients in the self-management cohort will choose to receive an intervention that consists of education, nutrition/diet modification, lifestyle change recommendation, medication review, and psychology support based on Social Cognition Theory (SCT). The patients in the control cohort will do regular follow-ups based on the clinic rules. All the patients will be followed up for 5 years, or until the occurrence of a primary outcome. Detailed clinical, laboratory markers, nutritional status, psychological exposures and outcome questionaries will be collected semiannually in CKD stage 1-2 and trimonthly in stage 3-5 patients. The primary outcome is the occurrence of composite clinical endpoints (doubling of serum creatinine level, ESKD, loss of renal function (≥ 40% decline in GFR from baseline), death, major cardiovascular or cerebrovascular events). The main secondary outcomes include the absolute change and slope of eGFR, absolute changes of urinary protein creatinine ratio, 24-h urine proteinuria, intact parathyroid hormone level, and self-management adherence rate and quality of life from baseline to end of the study. The effectiveness of self-management will be analyzed and the association between longitudinal trajectories of self-management and renal outcomes will be evaluated. DISCUSSION: This study aims to provide further evidence for the effectiveness of theory-based self-management in CKD patients and to improve the lives of patients with CKD by slowing progression, improving psychological well-being and overall quality of life. TRIAL REGISTRATION: Chinese Clinical Trial Register (ChiCTR1900024633). 19 July, 2019. http://www.chictr.org.cn/showproj.aspx?proj=38378.

The reproductive endocrine feature and conception outcome of women with unknown etiological menstrual cycle (36-45 days) with long follicular phase.

OBJECTIVE: To explore the reproductive endocrine feature and conception outcome of women with unknown etiological long menstrual cycle (LMC) (36-45 days) with long follicular phase. METHODS: In the cohort study, we included 80 women with unknown etiological long menstrual cycle of biphasic basal body temperature (BBT) lasting for 36-45 days and 87 controls with normal cycle of biphasic BBT into LMC group and NMC group, respectively. Serum hormone levels, fasting glucose, and insulin of participants were tested, and ovulation was observed by ultrasound. The conception outcome was followed up within 12 menstrual cycles. RESULTS: In the LMC group, the rate of abnormality of HOMA-insulin resistance index (40.0% vs. 20.7%, p < .01), luteal phase defect (30.9% vs. 13.8%, p < .05) and abnormality of FSH/LH ratio (15.6% vs. 5.7%, p < .05) were all significantly higher, but the serum estradiol level on the day before ovulation (261.10 pg/mL vs. 320.26 pg/mL, p < .01) was lower. The rate of poor ovulation quality (31.3% vs.15.4%, p < .05) in the LMC group was significantly higher than the NMC group. In the LMC group, the natural conception rate within 12 menstrual cycles was lower (41.9% vs. 66.2%, p < .01), whereas the spontaneous abortion rate in early pregnancy (29.0% vs. 9.8%, p < .05) and the conversion rate (21.6% vs. 5.2%, p < .01) to anovulation within 12 cycles were significantly higher. CONCLUSIONS: Women with unknown etiological menstrual cycle (36-45 days) with long follicular phase have greater endocrine abnormality and higher risk of spontaneous abortion, infertility, and conversion to anovulation. Moderate early intervention may be advisable for these women, especially those who wish to get pregnant.

Association between prenatal antibiotics exposure and measures of fetal growth: A repeated-measure study.

The abuse of antibiotics in animal husbandry has brought many public health problems, among which the passive use of antibiotics caused by eating food containing residual antibiotics has attracted the most attention. However, few studies have examined the possible adverse effects of prenatal antibiotics exposure on fetal growth and development. In this study, we investigated the associations between prenatal antibiotics exposure and measures of fetal growth. A total of 429 mother-newborn pairs from a birth cohort were enrolled and spot urine samples (N = 1287) were collected during each trimester of pregnancy. Sixteen antibiotics from 7 categories, were selected for the determination of the targeted antibiotics in maternal urines by UHPLC-MS/MS. Fetal growth indicators including newborn birth weight, birth length and gestational age (GA), were obtained from medical record. Sixteen antibiotics were found in 92.3% of the urine samples with detection frequencies ranging from 0.3% to 41.3%. Among the 16 antibiotics detected, we found that the exposure level of ciprofloxacin in the first trimester of pregnancy was negatively correlated with GA (ß = -0.17 day, 95% CI, -0.32 to -0.02 day), which would increase the risk of preterm birth (OR=1.05, 95% CI, 1.00, 1.09). The exposure level of norfloxacin in the second trimester of pregnancy was negatively correlated with fetal birth weight (ß = -17.56 g, 95% CI, -31.13 to -3.99 g) and birth length (ß = -0.05 cm, 95% CI, -0.08 to -0.02 cm), and the exposure level of sulfamethoxazole in the third trimester of pregnancy was negatively correlated with fetal birth length (ß = -0.15 cm, 95% CI, -0.29 to -0.02 cm). Our findings suggest that prenatal exposure to norfloxacin and sulfamethoxazole may adversely affect fetal growth and development.

Machine learning algorithms' accuracy in predicting kidney disease progression: a systematic review and meta-analysis.

BACKGROUND: Kidney disease progression rates vary among patients. Rapid and accurate prediction of kidney disease outcomes is crucial for disease management. In recent years, various prediction models using Machine Learning (ML) algorithms have been established in nephrology. However, their accuracy have been inconsistent. Therefore, we conducted a systematic review and meta-analysis to investigate the diagnostic accuracy of ML algorithms for kidney disease progression. METHODS: We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, the Chinese Biomedicine Literature Database, Chinese National Knowledge Infrastructure, Wanfang Database, and the VIP Database for diagnostic studies on ML algorithms' accuracy in predicting kidney disease prognosis, from the establishment of these databases until October 2020. Two investigators independently evaluate study quality by QUADAS-2 tool and extracted data from single ML algorithm for data synthesis using the bivariate model and the hierarchical summary receiver operating characteristic (HSROC) model. RESULTS: Fifteen studies were left after screening, only 6 studies were eligible for data synthesis. The sample size of these 6 studies was 12,534, and the kidney disease types could be divided into chronic kidney disease (CKD) and Immunoglobulin A Nephropathy, with 5 articles using end-stage renal diseases occurrence as the primary outcome. The main results indicated that the area under curve (AUC) of the HSROC was 0.87 (0.84-0.90) and ML algorithm exhibited a strong specificity, 95% confidence interval and heterogeneity (I2) of (0.87, 0.84-0.90, [I2 99.0%]) and a weak sensitivity of (0.68, 0.58-0.77, [I2 99.7%]) in predicting kidney disease deterioration. And the the results of subgroup analysis indicated that ML algorithm's AUC for predicting CKD prognosis was 0.82 (0.79-0.85), with the pool sensitivity of (0.64, 0.49-0.77, [I2 99.20%]) and pool specificity of (0.84, 0.74-0.91, [I2 99.84%]). The ML algorithm's AUC for predicting IgA nephropathy prognosis was 0.78 (0.74-0.81), with the pool sensitivity of (0.74, 0.71-0.77, [I2 7.10%]) and pool specificity of (0.93, 0.91-0.95, [I2 83.92%]). CONCLUSION: Taking advantage of big data, ML algorithm-based prediction models have high accuracy in predicting kidney disease progression, we recommend ML algorithms as an auxiliary tool for clinicians to determine proper treatment and disease management strategies.

Stigmasterol sensitizes endometrial cancer cells to chemotherapy by repressing Nrf2 signal pathway.

BACKGROUND: Chemoresistance reduces the 5-year survival rate of endometrial cancer patient, which is the current major obstacle for cancer therapy. Increasing evidence state that Nrf2 contributes to chemoresistance in several kinds of cancer. However, its role in endometrial cancer cells remains unclarified. METHODS: Immunohistochemistry staining was used to detect the expression of Nrf2 in normal patient and endometrial cancer patient. Stable transfection Ishikawa cell line with high level of Nrf2 was established to evaluate its role in chemoresistance. Dot blot assays were used to assess global hydroxymethylation level after stigmasterol treatment. Cellular growth profile was detected by CCK8 assay. Western blot was used to evaluate the changes of the target molecules after various treatments. RESULTS: Nrf2 is overexpressed in endometrial cancer tissues compared with the normal endometrium. Overexpression of Nrf2 resulted in decrease sensitivity to cisplatin. In addition, stigmasterol has been identified as a novel Nrf2 inhibitor. It enhanced the sensitivity of endometrial cancer cells to cisplatin, and the underlying mechanism is that stigmasterol declines the Nrf2 protein level. CONCLUSIONS: Our findings identified stigmasterol as a new potential inhibitor of Nrf2 and highlight a critical role of stigmasterol in overcoming chemoresistance in endometrial cancer therapy.

USP18 promotes cell proliferation and suppressed apoptosis in cervical cancer cells via activating AKT signaling pathway.

BACKGROUND: The deubiquitinating (DUB) enzyme ubiquitin-specific protease 18 (USP18), also known as UBP43, is an ubiquitin-specific protease linked to several human malignancies. However, USP18's underlying function in human cervical cancer remains unclear. In the current study, we aimed to analyse the role of USP18 and its signalling pathways in cervical cancer. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical staining were performed to analyse USP18 levels in cervical cancer and matched to adjacent normal tissues. Moreover, RNA interference (RNAi) and lentiviral-mediated vector transfections were performed to silence and overexpress USP18, respectively, in cervical cancer cells. Further, Cell Counting Kit-8 (CCK-8) and Annexin V/PI staining assays were used to assess its biological function in cell proliferation and apoptosis, respectively. A xenograft model was used to examine USP18's function in vivo. RESULTS: The present findings demonstrated that USP18 was overexpressed in cervical cancer specimens and cell lines. Silencing USP18 in SiHa and Caski cervical cancer cell lines inhibited cell proliferation, induced apoptosis, and promoted cleaved caspase-3 expression. In contrast, USP18 overexpression showed the opposite effects in human HcerEpic cells. A Gene Set Enrichment Analysis revealed that USP18 was enriched in the PI3K/AKT signalling pathway in cervical cancer. Hence, the PI3K/AKT inhibitor LY294002 was used to determine the relationship between USP18 and AKT in cervical cancer cells. Importantly, LY294002 significantly abolished the effects of USP18 overexpression in cervical cancer cells. In vivo, USP18 silencing inhibited human cervical cancer cells' tumorigenicity. CONCLUSIONS: The current study indicates that USP18 is an oncogenic gene in cervical cancer. Our findings not only deepened the understanding of USP18's biological function in cervical cancer pathogenesis, but we also provided novel insight for cervical cancer therapy. TRIAL REGISTRATION: Retrospectively registered.

Strategies to Mitigate the Bioactivation of Aryl Amines.

The bioactivation of xenobiotics to yield reactive metabolites can lead to tolerability and toxicity concerns within a drug discovery program. Development of strategies for mitigating the metabolic liability of commonly encountered toxicophores, such as anilines, relies on an understanding of the relative tendency of these functionalities to undergo bioactivation. In this report, we present the first systematic study of the structure-activity relationships of the bioactivation of aryl amine fragments (molecular weight < 250 Da) using a glutathione (GSH) trapping assay in the presence of human liver microsomes and the reduced form of nicotinamide adenine dinucleotide phosphate. This study demonstrates that conversion of anilines to nitrogen-containing heteroarylamines results in a lower abundance of GSH conjugates in the order phenyl > pyrimidine ≈ pyridine > pyridazine. Introduction of electron-withdrawing functionality on the aromatic ring had a less pronounced effect on the extent of GSH conjugation. Examination of more drug-like compounds sourced from in-house drug discovery programs revealed similar trends in bioactivation between matched pairs containing (hetero)aryl amines. This study provides medicinal chemists with insights and qualitative guidance for the minimization of risks related to aryl amine metabolism.

Hydroxysafflor Yellow A Confers Neuroprotection from Focal Cerebral Ischemia by Modulating the Crosstalk Between JAK2/STAT3 and SOCS3 Signaling Pathways.

Natural bioactive compounds have increasingly proved to be promising in evidence- or target-directed treatment or modification of a spectrum of diseases including cerebral ischemic stroke. Hydroxysafflor yellow A (HSYA), a major active component of the safflower plant, has drawn more interests in recent year for its multiple pharmacological actions in the treatment of cerebrovascular and cardiovascular diseases. Although the Janus kinase signaling, such as JAK2/STAT3 pathway, has been implicated in the modulation of the disease, the inhibition or activation of the pathway that contributed to the neuronal prevention from ischemic damages remains controversial. In this study, a series of experiments were performed to examine the dose- and therapeutic time window-related pharmacological efficacies of HSYA with emphasis on the HSYA-modulated interaction of JAK2/STAT3 and SOCS3 signaling in the MCAO rats. We found that HSYA treatment significantly rescued the neurological and functional deficits in a dose-dependent manner in the MCAO rats within 3 h after ischemia. HSYA treatment with a dosage of 8 mg/kg or higher markedly downregulated the expression of the JAK2-mediated signaling that was activated in response to ischemic insult, while it also promoted the expression of SOCS3 coordinately. In the subsequent experiments with the use of the JAK2 inhibitor WP1066, we found that the treatment of WP1066 alone or combination of WP1066/HSYA all exhibited inhibitory effects on JAK2-mediated signaling, while there was no influence on the SOCS3 activity of corresponding efficacious data in the MCAO rats, suggesting that excessive activation of JAK2/STAT3 might be necessary for HSYA to provoke SOCS3-negative feedback signaling. Taking together, our study demonstrates that HSYA might modulate the crosstalk between JAK2/STAT3 and SOCS3 signaling pathways that eventually contributed to its therapeutic roles against cerebral ischemic stroke.

Mannoside-Modified Branched Gold Nanoparticles for Photothermal Therapy to MDA-MB-231 Cells.

Recently, gold nanoparticles (Au NPs) have been used to study the treatment of malignant tumors due to their higher biocompatibility and lesser toxicity. In addition, they can be excited through a specific wavelength to produce oscillating plasmonic photothermal therapy (PPTT) on the basis of the localized surface plasma resonance (LSPR) effect. Au NPs can be heated to kill cancer cells in specific parts of the body in a noninvasive manner. In this study, branched gold nanoparticles (BAu NPs) were prepared by mixing HAuCl4 in a 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer solution in a molar ratio of 1:2000. The UV-vis absorption peak was detected in the range of 700-1000 nm. Subsequently, BAu NPs were chemically linked to a thiol-modified mannoside molecule via a stable sulfur-Au covalent bond (Man@BAu NPs). Due to the presence of abundant mannose receptors on human-breast-cancer cells, MDA-MB-231, Man@BAu NPs were found to be abundant inside cancer cells. After irradiating the Man@BAu NP-laden MDA-MB231 switch with a near-infrared (NIR) laser at 808 nm wavelength, the photothermal-conversion effect raised the surface temperature of Man@BAu NPs, thus inducing cell death. Our experiment results demonstrated the advantages of applying Man@BAu NPs in inducing cell death in MDA-MB-231.

Potent and selective inhibitors of receptor-interacting protein kinase 1 that lack an aromatic back pocket group.

Receptor-interacting protein kinase 1 (RIPK1), a key component of the cellular necroptosis pathway, has gained recognition as an important therapeutic target. Pharmacologic inhibition or genetic inactivation of RIPK1 has shown promise in animal models of disease ranging from acute ischemic conditions, chronic inflammation, and neurodegeneration. We present here a class of RIPK1 inhibitors that is distinguished by a lack of a lipophilic aromatic group present in most literature inhibitors that typically occupies a hydrophobic back pocket of the protein active site. Despite not having this ubiquitous feature of many known RIPK1 inhibitors, we were able to obtain compounds with good potency, kinase selectivity, and pharmacokinetic properties in rats. The use of the lipophilic yet metabolically stable pentafluoroethyl group was critical to balancing the potency and properties of optimized analogs.

Discovery of potent azaindazole leucine-rich repeat kinase 2 (LRRK2) inhibitors possessing a key intramolecular hydrogen bond - Part 2.

The discovery of disease-modifying therapies for Parkinson's Disease (PD) represents a critical need in neurodegenerative medicine. Genetic mutations in LRRK2 are risk factors for the development of PD, and some of these mutations have been linked to increased LRRK2 kinase activity and neuronal toxicity in cellular and animal models. As such, research towards brain-permeable kinase inhibitors of LRRK2 has received much attention. In the course of a program to identify structurally diverse inhibitors of LRRK2 kinase activity, a 5-azaindazole series was optimized for potency, metabolic stability and brain penetration. A key design element involved the incorporation of an intramolecular hydrogen bond to increase permeability and potency against LRRK2. This communication will outline the structure-activity relationships of this matched pair series including the challenge of obtaining a desirable balance between metabolic stability and brain penetration.

The coordinating role of the human norovirus minor capsid protein VP2 is essential to functional change and nuclear localization of the major capsid protein VP1.

Global outbreaks of norovirus (NOV) gastroenteritis are associated with the most prevalent genotype, GII.4. Mutations in the protruding domain 2 (P2 domain) of the norovirus major capsid protein (VP1) result in the emergence of various NOV variants, however, it is unclear whether the minor capsid protein (VP2) also affects the generation of VP1 variants. In this study, using a human 293T expression system, we investigated the interactions of VP1 and VP2 of three GII.4 strains, focusing on the changes in expression and cellular localization. We found that co-transfection with VP1 and VP2 leads to a significant increase in expression of both proteins compared to that in cells transfected with VP1 or VP2 alone. In contrast to VP1 expressed in the absence of VP2, which was dispersed throughout the cytosol, VP2 expressed in the absence of VP1 was found to be located in the nucleus. This could be attributed to a predicted specific nuclear localization signal found in this gene. When both proteins were expressed, VP1 was found together with VP2 in the nucleus. These results thus suggest that the VP2 of GII.4 NOVs affects the function and cellular location of VP1 and that, with the cooperation of VP2, VP1 could play a critical role in affecting cell functions by impairing the downstream transcriptional signaling and chromatin remodeling in the cell nuclei.

Mechanism of MEK inhibition determines efficacy in mutant KRAS- versus BRAF-driven cancers.

KRAS and BRAF activating mutations drive tumorigenesis through constitutive activation of the MAPK pathway. As these tumours represent an area of high unmet medical need, multiple allosteric MEK inhibitors, which inhibit MAPK signalling in both genotypes, are being tested in clinical trials. Impressive single-agent activity in BRAF-mutant melanoma has been observed; however, efficacy has been far less robust in KRAS-mutant disease. Here we show that, owing to distinct mechanisms regulating MEK activation in KRAS- versus BRAF-driven tumours, different mechanisms of inhibition are required for optimal antitumour activity in each genotype. Structural and functional analysis illustrates that MEK inhibitors with superior efficacy in KRAS-driven tumours (GDC-0623 and G-573, the former currently in phase I clinical trials) form a strong hydrogen-bond interaction with S212 in MEK that is critical for blocking MEK feedback phosphorylation by wild-type RAF. Conversely, potent inhibition of active, phosphorylated MEK is required for strong inhibition of the MAPK pathway in BRAF-mutant tumours, resulting in superior efficacy in this genotype with GDC-0973 (also known as cobimetinib), a MEK inhibitor currently in phase III clinical trials. Our study highlights that differences in the activation state of MEK in KRAS-mutant tumours versus BRAF-mutant tumours can be exploited through the design of inhibitors that uniquely target these distinct activation states of MEK. These inhibitors are currently being evaluated in clinical trials to determine whether improvements in therapeutic index within KRAS versus BRAF preclinical models translate to improved clinical responses in patients.

Clonal spread and azole-resistant mechanisms of non-susceptible Candida albicans isolates from vulvovaginal candidiasis patients in three Shanghai maternity hospitals.

In our multicenter study, 43 fluconazole non-susceptible and 45 fluconazole-susceptible isolates were collected from vulvovaginal candidiasis (VVC) patients from three Shanghai maternity hospitals to analyze their molecular epidemiological features and fluconazole resistant mechanisms. Cross-resistance to fluconazole, itraconazole and voriconazole was observed in 53.5% of the nonsusceptible isolates. Though we acquired 12 clonal complexes (CCs) of diploid sequence types (DSTs) in clinical isolates by a multilocus sequence typing method, fluconazole nonsusceptible isolates all belonged to CC69 with a predominant genotype of DST 79. Increased expressions of efflux pump genes (CDR1, CDR2, and MDR1) were observed only in minor fluconazole non-susceptible isolates by real-time quantitative polymerase chain reaction (PCR). However, ERG11 genes of fluconazole SDD and resistant isolates had significantly higher expression levels than fluconazole-susceptible isolates. Moreover, 13 distinct amino acid substitutions in Erg11p were found in clinical isolates. Three of the substitutions were novel amino acid substitutions (T123I, P98S, and Y286D), which were not in the susceptible isolates. Only two heterozygous amino acid substitutions (A18P/A and R365G/R) in Erg3p were found in two isolates with cross-resistance to fluconazole, itraconazole, and voriconazole. Taken together, we observed the clonal spread of CC69 in fluconazole non-susceptible isolates of Candida albicans from VVC patients with the dominant genotype DST79. ERG11 gene mutations and overexpression predominantly contributed to fluconazole resistance instead of the more common increased expressions of efflux pump genes (CDR1, CDR2, and MDR1).

A computational study of the Fenton reaction in different pH ranges.

The reaction of iron(ii) and hydrogen peroxide, namely the Fenton reaction, is well-known for its strong oxidizing capability. While the Fenton reactions are ubiquitous and have wide applications in many areas, the detailed mechanism, especially the nature of the reactive intermediates responsible for oxidation, is not completely clear. In this work, the performances of various density functional theory (DFT) methods on the relative energies of key Fenton intermediates are evaluated. The DFT method selected from the benchmark study is then exploited to investigate the aqueous Fenton reactions in different pH conditions. The results show that at pH > 2.2, the major Fenton oxidants are high-valent oxoiron(iv) aquo complexes. However, depending on the pH conditions, these complexes can exist in three protonation states that display quite different oxidation reactivities. The oxidizing power of FeIV[double bond, length as m-dash]O is found to be principally determined by the total charge of the ligands and is less influenced by the axial ligand effect. Moreover, the calculations reveal that the presence of the hydronium ion can stabilize the intermediate of the hydroxyl radical and further inhibit oxoiron(iv) formation via proton transfer. The contribution of hydroxyl radicals could compete with the oxoiron(iv) species at pH below 2.2. In addition, high-level ab initio calculations question the existence of the iron(iv)-dihydroxo intermediate suggested in the literature. The implications of the computational results for the Fenton oxidation process, cytochrome P450, and catalyst design are discussed.

Time-resolved FTIR study of light-driven sodium pump rhodopsins.

Light-driven sodium ion pump rhodopsin (NaR) is a new functional class of microbial rhodopsin. A previous flash photolysis study of Krokinobacter eikastus rhodopsin 2 (KR2) revealed the presence of three kinetically distinct intermediates: K, L/M, and O. Previous low-temperature Fourier-transform infrared (FTIR) spectroscopy of KR2 showed that photoisomerization from the all-trans to the 13-cis form is the primary event of the Na+ pumping photocycle, but structural information on the subsequent intermediates is limited. Here, we applied step-scan time-resolved FTIR spectroscopy to KR2 and Nonlabens dokdonensis rhodopsin 2 (NdR2). Both low-temperature static and time-resolved FTIR spectra resolved a K-like intermediate, and the corresponding spectra showed few differences. Strong hydrogen-out-of-plane (HOOP) vibrations, which appeared in the K intermediate, are common among other rhodopsins. It is, however, unique for NaR that such HOOP bands are persistent in late intermediates, such as L and O intermediates. This observation strongly suggests similar chromophore structures for the K, L, and O intermediates. In fact, an isotope-labeled study that used 12,14-D2 retinal revealed that the chromophore configuration of the O intermediate in NaR is 13-cis. In contrast to the vibrations of the chromophore, those of the protein differ among intermediates, and this is related to the sodium-pumping function. The molecular mechanism of the light-driven sodium pump is discussed on the basis of the present time-resolved FTIR results.