Discovery and characterization of the flavonoids in Cortex Mori Radicis as naturally occurring inhibitors against intestinal nitroreductases.

Gut bacterial nitroreductases are found to be heavily related with the intestinal toxicity of nitroaromatic compounds in food or medicine, which can be converted into mutagenic and enterotoxic nitroso or N-hydroxyl intermediates. Thus, inhibiting the gut microbe-encoded nitroreductases has become an attractive method to reduce the mutagen metabolites in colon and prevent intestinal diseases. In this study, the inhibitory effects of sixteen constituents in Cortex Mori Radicis on two kinds of gut bacterial nitroreductases (EcNfsA and EcNfsB) were evaluated with nitrofurazone (NFZ) as substrate and NADPH as electron donor. The results clearly demonstrated that four flavonoids including kuwanon G, kuwanon A, sanggenol A and kuwanon C showed dual inhibition on both EcNfsA and EcNfsB mediated NFZ reduction; morusin, morin, and sanggenone C were strong inhibitors towards EcNfsA; kuwanon H and kuwanon E exhibited effective inhibition on EcNfsB. Further inhibition kinetic analysis and molecular docking simulations displayed that all inhibitors above suppressed both EcNfsA and EcNfsB activities in competitive manners, except non-competitive inhibition of morin on EcNfsA and non-competitive inhibition of kuwanon C on EcNfsB, respectively. Taking together, these findings revealed that most flavonoids in Cortex Mori Radicis presented effective inhibition on gut microbial nitroreductases, suggesting that Cortex Mori Radicis might be a promising candidate for ameliorating nitroreductases mediated intestinal mutagenicity.

Utility of multidetector computed tomography quantitative measurements in identifying sarcopenia: a propensity score matched study.

OBJECTIVE: To evaluate the utility of multidetector computed tomography MDCT quantitative measurements in identifying sarcopenia. MATERIALS AND METHODS: The clinical data and MDCT images of 64 patients of sarcopenia and 184 non-sarcopenic participants between October 2020 and January 2021were retrospectively analyzed. Propensity score matching was used to match the sarcopenic patients with the non-sarcopenic participants. Two radiologists independently measured the cross-sectional area (CSA) of skeletal muscle and intramuscular fat tissue and CT density of skeletal muscle at the middle L3 vertebral level on CT images of all participants. Intra-observer agreement was evaluated via intraclass correlation coefficients (ICC). A receiver operating characteristic (ROC) curve was built for each variable. Correlations between CT parameters and clinical data were assessed via Pearson or Spearman correlation coefficient. RESULTS: A total of 74 participants (mean age 72 ± 4 years, range 66-85 years; 38 men and 36 women) were included, comprising 37 sarcopenic patients and 37 non-sarcopenic participants. There were no significant intergroup differences regarding age, sex ratio, and body mass index (BMI) (P < 0.05). The CSA and density of skeletal muscle measured by two radiologists were reliable (ICC ≥ 0.75, P < 0.001). Compared with the sarcopenic group, the non-sarcopenic group had a significantly greater CSA and CT density of the total skeletal muscle (TSM) and paraspinal skeletal muscle (PSM) and skeletal muscle index at L3 level (L3 SMI) (P < 0.05). The fat infiltration ratio (FIR) of TSM, PSM, and psoas muscle was significantly higher in the sarcopenic group than that in non-sarcopenic participants (P < 0.05). ROC curve analysis showed the PSM FIR + PSM CT density (PSM D) had the best predictive value for sarcopenia (AUC = 0.836). The PSM FIR and age were moderately positively correlated (r = 0.410, P < 0.001). CONCLUSION: Fat infiltration of skeletal muscle had better predictive value than L3 SMI in the diagnosis of sarcopenic. The PSM FIR + PSMD had the best predictive value for sarcopenia, which was moderately positively correlated with age.

Association Between the Cardiometabolic Index and Hyperuricemia in an Asymptomatic Population with Normal Body Mass Index.

BACKGROUND AND PURPOSE: The association between the cardiometabolic index (CMI) and hyperuricemia was investigated to provide theoretical support for the management of hyperuricemia in an asymptomatic population with normal body mass index (BMI). METHODS: A cross-sectional study was carried out among 374 asymptomatic adults with normal BMI. Traditional anthropometric indices and CMI were calculated. Anthropometric indices were divided into four quartiles and multivariate logistic analysis was used to analyze the association between these indices and hyperuricemia. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were used to evaluate the power of the indices to predict hyperuricemia values. The DeLong test was used to compare the AUC of different anthropometric indices. RESULTS: After adjusting for confounding variables, the CMI exhibited a stronger association with hyperuricemia than other anthropometric indices. The odds ratio (OR) for hyperuricemia in the highest quartile of the CMI was 16.674 (confidence interval [CI]=4.424-62.846). The AUC of the CMI was 0.777 (95% CI=0.719-0.835, p<0.001), which was higher than the values for other anthropometric indices. The differences in AUC between the CMI and other indices were statistically significant; the optimal cutoff value of the CMI was 0.655, with sensitivity of 57.1% and specificity of 84.2%. CONCLUSION: The CMI, which combines waist circumference, height and blood lipid parameters, was more strongly associated with hyperuricemia than other anthropometric indices in asymptomatic population with normal BMI. The CMI may serve as a potential monitoring indicator for hyperuricemia management in asymptomatic populations with normal BMI.

Molecular basis for kinin selectivity and activation of the human bradykinin receptors.

Bradykinin and kallidin are endogenous kinin peptide hormones that belong to the kallikrein-kinin system and are essential to the regulation of blood pressure, inflammation, coagulation and pain control. Des-Arg10-kallidin, the carboxy-terminal des-Arg metabolite of kallidin, and bradykinin selectively activate two G protein-coupled receptors, type 1 and type 2 bradykinin receptors (B1R and B2R), respectively. The hyperactivation of bradykinin receptors, termed 'bradykinin storm', is associated with pulmonary edema in COVID-19 patients, suggesting that bradykinin receptors are important targets for COVID-19 intervention. Here we report two G protein-coupled complex structures of human B1R and B2R bound to des-Arg10-kallidin and bradykinin, respectively. Combined with functional analysis, our structures reveal the mechanism of ligand selectivity and specific activation of the bradykinin receptor. These findings also provide a framework for guiding drug design targeting bradykinin receptors for the treatment of inflammation, cardiovascular disorders and COVID-19.

A complex structure of arrestin-2 bound to a G protein-coupled receptor.

Arrestins comprise a family of signal regulators of G-protein-coupled receptors (GPCRs), which include arrestins 1 to 4. While arrestins 1 and 4 are visual arrestins dedicated to rhodopsin, arrestins 2 and 3 (Arr2 and Arr3) are ß-arrestins known to regulate many nonvisual GPCRs. The dynamic and promiscuous coupling of Arr2 to nonvisual GPCRs has posed technical challenges to tackle the basis of arrestin binding to GPCRs. Here we report the structure of Arr2 in complex with neurotensin receptor 1 (NTSR1), which reveals an overall assembly that is strikingly different from the visual arrestin-rhodopsin complex by a 90° rotation of Arr2 relative to the receptor. In this new configuration, intracellular loop 3 (ICL3) and transmembrane helix 6 (TM6) of the receptor are oriented toward the N-terminal domain of the arrestin, making it possible for GPCRs that lack the C-terminal tail to couple Arr2 through their ICL3. Molecular dynamics simulation and crosslinking data further support the assembly of the Arr2‒NTSR1 complex. Sequence analysis and homology modeling suggest that the Arr2‒NTSR1 complex structure may provide an alternative template for modeling arrestin-GPCR interactions.

Alterations of the oral microbiome in patients treated with the Invisalign system or with fixed appliances.

INTRODUCTION: Although the Invisalign system has been used widely in recent years, the influences of this treatment on the oral microbiome and whether or not this influence is different from that of fixed appliances is still unknown. In this study, we investigated the changes in the oral microbiome in patients treated with the Invisalign system or with fixed appliances. METHODS: Fifteen subjects were enrolled, comprising 5 fixed appliance patients, 5 Invisalign patient, and 5 healthy controls. Saliva samples were collected, and high-throughput pyrosequencing was performed based on the 16S rRNA gene. RESULTS: Both fixed and Invisalign orthodontic treatments resulted in dysbiosis of the oral microbiome. Firmicutes and TM7 at the phyla level and Neisseria at the genus level displayed statistically significant differences between the 2 orthodontic groups. The effect of these changes with microbiome on oral health was inconsistent. The inferred microbial function of the Invisalign group suggested this group was more predisposed to periodontal diseases. CONCLUSION: The influence of the Invisalign system on the oral microbiome was no better for oral health compared with fixed appliances. The convenience of maintaining oral hygiene rather than changes in the oral microbiome may be the underlying reason for the performance of the Invisalign system on oral health.

Ligand-induced activation of ERK1/2 signaling by constitutively active Gs-coupled 5-HT receptors.

5-HT4R, 5-HT6R, and 5-HT7AR are three constitutively active Gs-coupled 5-HT receptors that have key roles in brain development, learning, memory, cognition, and other physiological processes in the central nervous system. In addition to Gs signaling cascade mediated by these three 5-HT receptors, the ERK1/2 signaling which is dependent on cyclic adenosine monophosphate (cAMP) production and protein kinase A (PKA) activation downstream of Gs signaling has also been widely studied. In this study, we investigated these two signaling pathways originating from the three Gs-coupled 5-HT receptors in AD293 cells. We found that the phosphorylation and activation of ERK1/2 are ligand-induced, in contrast to the constitutively active Gs signaling. This indicates that Gs signaling alone is not sufficient for ERK1/2 activation in these three 5-HT receptors. In addition to Gs, we found that ß-arrestin and Fyn are essential for the activation of ERK1/2. Together, these results put forth a novel mechanism for ERK1/2 activation involving the cooperative action of Gs, ß-arrestin, and Fyn.

[Correlation of single nucleotide polymorphisms rs995030 and rs4474514 of the KITLG gene with male infertility].

OBJECTIVE: To investigate the correlation of the single nucleotide polymorphisms rs995030 and rs4474514 of the tyrosine kinase receptor-specific ligand (KITLG) gene with the risk of male infertility. METHODS: This study included 360 patients with idiopathic male infertility and 338 healthy fathers as controls, all from the surrounding areas of Nanjing. According to the 5th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, we divided the infertility patients into an azoospermia (n = 143), a severe oligozoospermia (n = 159), and an oligozoospermia group (n = 58). We obtained the basic clinical data on all the subjects, collected genomic DNA from the peripheral blood of the patients, determined the genotypes of the KITLG gene rs995030 and rs4474514 by sequence mass-array, and analyzed the correlation between the two-point gene polymorphism and male infertility by logistic regression analysis. RESULTS: Statistically significant differences were observed between the infertility patients and normal fertile controls in sperm concentration (ï¼»13.23 ± 24.52ï¼½ vs ï¼»78.74 ± 61.25ï¼½ ×106/ml, P < 0.01), the percentage of progressively mobile sperm (ï¼»18.71 ± 15.19ï¼½% vs ï¼»39.36 ± 9.75ï¼½%, P < 0.01), and the level of FSH (ï¼»16.09 ± 17.31ï¼½ vs ï¼»4.56 ± 2.41ï¼½ IU/L, P < 0.01), but not between the genotypes and male infertility, and no correlation was found in subgroup analysis. CONCLUSIONS: The single nucleotide polymorphisms rs995030 and rs4474514 of the KITLG gene were not significantly correlated with male infertility, which is to be further verified by more studies with samples of larger size and expanded selection range.

[Correlation of the single nucleotide polymorphisms rs34349826 and rs6521 of the LHB gene with male infertility in Chinese men].

Objective: To study the relationship of the single nucleotide polymorphisms (SNP) rs34349826 (c.104 A>G) and rs6521 (c.114 C>G) of the luteinizing hormone beta-subunit (LHB) gene with male infertility in Chinese men. METHODS: This case-control study included 405 males with primary infertility (the infertility group) and 424 normal fertile men (the control group), the former again divided into subgroups of oligospermia, severe oligozoospermia and azoospermia according to the sperm concentration. Clinical data were collected from all the subjects and genomic DNA obtained from their peripheral blood for genotyping rs34349826 and rs6521 of the LHB gene by Sequence MassArray. We analyzed the correlation of male infertility with the SNPs of the two loci using the logistic regression model as well as its association with their haplotype combination with the SHEsis online software. RESULTS: There were statistically significant differences between the control and infertility groups in the semen volume (ï¼»3.51 ± 1.36ï¼½ vs ï¼»3.74 ± 1.71ï¼½ ml, P <0.05), sperm concentration (ï¼»79.21 ± 61.60ï¼½ vs ï¼»27.37 ± 30.80ï¼½ ×106/ml, P <0.01), percentage of progressively motile sperm (ï¼»39.40 ± 9.64ï¼½ % vs ï¼»11.90 ± 14.72ï¼½ %, P <0.01), and levels of serum luteinizing hormone (LH) (ï¼»3.29 ± 1.39ï¼½ vs ï¼»6.25 ± 4.83ï¼½ IU/L, P <0.01) and follicle-stimulating hormone (FSH) (ï¼»4.56 ± 2.31ï¼½ vs ï¼»15.64 ± 17.03ï¼½ IU/L, P <0.01). Logistic regression analysis revealed no correlation between male infertility and the genotypes of the rs34349826 and rs6521 loci of the LHB gene, and similar results were found in the subgroups of the infertile males. SHEsis analysis on the haplotypes of the rs34349826 and rs6521 loci showed the GG genotype combination to be a protective factor against male infertility. CONCLUSIONS: The rs34349826 and rs6521 loci of the LHB gene were not related to male infertility, which can be further confirmed by larger-sample studies. The GG genotype combination is a protective factor against male infertility.

[Multiplex fluorescence PCR for detection of Y Chromesome microdeletions].

OBJECTIVE: Detection of azoospermia factor (AZF) microdeletions on the Y chromosome is one of the auxiliary strategies recognized at home and abroad for the examination of male infertility. Traditional PCR gel electrophoresis fails to meet the clinical needs due to its shortcomings. The purpose of this study was to explore the feasibility of multiplex fluorescence PCR in the detection of AZF microdeletions. METHODS: We collected samples of Y chromosomal AZF microdeletions from 238 patients with azoospermia or oligozoospermia and 62 normal males, identified the 14 short tandem repeat (STR) loci in the AZF region of the Y chromosome by multiplex PCR gel electrophoresis and multiplex fluorescence PCR, and analyzed the consistency in the results of the two methods by Kappa test. RESULTS: There was a perfect consistency between multiplex PCR gel electrophoresis and multiplex fluorescence PCR in the detection rate of the STR loci in the 300 samples. Kappa test showed both P and Kappa values to be 1 for the 6 loci in the AZFa, AZFb and AZFc regions of the Y chromosome, with no statistically significant difference between the two methods. CONCLUSIONS: Multiplex fluorescence PCR can save a lot of time, reduce workload and improve laboratory efficiency and therefore is preferable to multiplex PCR gel electrophoresis in detecting Y chromosome microdeletions.

Identification and biochemical characterization of DC07090 as a novel potent small molecule inhibitor against human enterovirus 71 3C protease by structure-based virtual screening.

Hand, foot and mouth disease (HFMD) is a serious, highly contagious disease. HFMD caused by Enterovirus 71 (EV71), results in severe complications and even death. The pivotal role of EV71 3Cpro in the viral life cycle makes it an attractive target for drug discovery and development to treat HFMD. In this study, we identified novel EV71 3Cpro inhibitors by docking-based virtual screening. Totally 50 compounds were selected to test their inhibitory activity against EV71 3Cpro. The best inhibitor DC07090 exhibited the inhibition potency with an IC50 value of 21.72 ± 0.95 µM without apparent toxicity (CC50 > 200 µM). To explore structure-activity relationship of DC07090, 15 new derivatives were designed, synthesized and evaluated in vitro enzyme assay accordingly. Interestingly, four compounds showed inhibitory activities against EV71 3Cpro and only DC07090 inhibited EV71 replication with an EC50 value of 22.09 ± 1.07 µM. Enzyme inhibition kinetic experiments showed that the compound was a reversible and competitive inhibitor. The Ki value was determined to be 23.29 ± 12.08 µM. Further molecular docking, MD simulation and mutagenesis studies confirmed the binding mode of DC07090 and EV71 3Cpro. Besides, DC07090 could also inhibit coxsackievirus A16 (CVA16) replication with an EC50 value of 27.76 ± 0.88 µM. Therefore, DC07090 represents a new non-peptidyl small molecule inhibitor for further development of antiviral therapy against EV71 or other picornaviruses.