Comparative investigation of transport and deposition of nebulized particles in nasal airways following various middle turbinectomy

BACKGROUND

Topical intranasal medication is required following functional endoscopic sinus surgery (FESS). The optimal particle size of transnasal nebulization aimed at the sinonasal cavities is not conclusive. The current study aims to evaluate the effect of particle size and various surgery scope of middle turbinectomy (MT) on post-full FESS drug delivery to the sinonasal cavities.

METHODS

Sinonasal reconstructions were performed from post-full FESS CT scans in 6 chronic rhinosinusitis with nasal polyps (CRSwNP) patients. Four additional models representing alternative surgery scopes of MT were established from each post-FESS reconstruction for simulation data comparison. Airflow and particle deposition of nebulized delivery were simulated via computational fluid dynamics (CFD) and validated through in vitro experiments. The optimal particle sizes reaching a deposition of at least 75% of the maximum in the targeted regions were identified.

RESULTS

The drug deposition rate onto the targeted regions increased following MT, with the greatest deposition following posterior MT (P-MT). Droplets in the range of 18-26 μm reached a deposition of larger than 75% of the maximum onto the targeted regions. Drug delivery rate in the sinonasal cavities varied significantly among individuals and across different types of MT with varying surgical scopes.

CONCLUSIONS

This study is the first to investigate the effect of various surgery scope on drug delivery by transnasal nebulization to the sinonasal cavities. The findings strongly affirm the vast potential of transnasal nebulization as an effective post-FESS treatment option. Moreover, it emphasizes that the drug delivery process via atomizers to the nasal cavity and paranasal sinuses is highly sensitive to the particle size.

Computational Chemistry in Structure-Based Solute Carrier Transporter Drug Design: Recent Advances and Future Perspectives

Solute carrier transporters (SLCs) are a class of important transmembrane proteins that are involved in the transportation of diverse solute ions and small molecules into cells. There are approximately 450 SLCs within the human body, and more than a quarter of them are emerging as attractive therapeutic targets for multiple complex diseases, e.g., depression, cancer, and diabetes. However, only 44 unique transporters (∼9.8% of the SLC superfamily) with 3D structures and specific binding sites have been reported. To design innovative and effective drugs targeting diverse SLCs, there are a number of obstacles that need to be overcome. However, computational chemistry, including physics-based molecular modeling and machine learning- and deep learning-based artificial intelligence (AI), provides an alternative and complementary way to the classical drug discovery approach. Here, we present a comprehensive overview on recent advances and existing challenges of the computational techniques in structure-based drug design of SLCs from three main aspects: (i) characterizing multiple conformations of the proteins during the functional process of transportation, (ii) identifying druggability sites especially the cryptic allosteric ones on the transporters for substrates and drugs binding, and (iii) discovering diverse small molecules or synthetic protein binders targeting the binding sites. This work is expected to provide guidelines for a deep understanding of the structure and function of the SLC superfamily to facilitate rational design of novel modulators of the transporters with the aid of state-of-the-art computational chemistry technologies including artificial intelligence.

ELABELA-APJ Axis Enhances Mesenchymal Stem Cell Proliferation and Migration via the METTL3/PI3K/AKT Pathway

Mesenchymal stem cells (MSCs) possess a strong therapeutic potential in regenerative medicine. ELABELA (ELA) is a 32 amino acid peptide that binds to the apelin peptide jejunum receptor (APJ) to regulate cell proliferation and migration. The aim of this study was to investigate the function of ELA vis-a-vis the MSC proliferation and migration, and further explore the underlying mechanism. We demonstrated that the exogenous supplement of ELA boosts the proliferation and migration ability of MSCs, alongside improved in vitro cell viability. These capabilities were rendered moot upon APJ knockdown. In addition, ELA (5-20 μM) was shown to upregulate the expression of METTL3 in a concentrationdependent pattern, a capacity which was suppressed by APJ reduction, whereas the downregulation of METTL3 expression blocked the beneficial effects induced by ELA. ELA was also observed to upregulate the phosphorylation level of AKT. This ELA-induced activation of the PI3K/AKT pathway, however, is inhibited with knockdown of METTL3. Our data indicate that ELA could act as a promoter of MSC proliferation and migration in vitro through the APJ receptor, something which might be attributed to the activation of the METTL3/PI3K/AKT signaling pathway. Therefore, ELA is a candidate for optimizing MSC-based cell therapy, while METTL3 is a potential target for its promoting action on MSCs.

[Efficacy of Hintermann calcaneal lengthening osteotomy for flexible flatfoot]

Objective: To investigate the clinical efficacy of Hintermann osteotomy (H-LCL) for flexible flatfoot. Methods: A follow-up study. Clinical data of 30 patients with flexible flatfoot treated with H-LCL operation from January 2020 to December 2021 in Sports Medical Center of the First Affiliated Hospital of Army Medical University were retrospectively analyzed. There were 8 males and 22 females, with a mean age of (39.0±15.2) years. The mean time from symptom onset to the diagnosis［M（Q₁，Q₃）］was 24.0 (5.5, 102.0) months. The functional and imaging scores of the patients before and after the last follow-up were compared to evaluate the clinical efficacy of the operation. The functional scores included American Orthopedic Foot and Ankle Society (AOFAS) score, visual analogue scale (VAS) of pain, pain interference (PI) and physical function (PF) index in Patient-Reported Outcomes Measurement Information System (PROMIS). And the imaging scores included Meary's angle, calcaneal pitch angle, calcaneal valgus angle and talonavicular coverage angle. Results: The mean operation time was (82.3±24.4) min, and the follow-up periods was (17.9±6.9) months. At the last follow-up, VAS of pain [M(Q₁, Q₃)] decreased from 5 (4, 6) to 2 (1, 2); PI decreased from 59.8±5.0 to 44.6±5.7; AOFAS increased from 65.2±10.0 to 85.8±3.3; PF increased from 50 (48.5,51.0) to 58.5 (54.0, 66.0); Meary's angle (antero-posterior image) decreased from 15.7° (10.1°, 29.2°) to 3.9° (2.6°, 5.3°); Meary's angle (lateral image) decreased from 13.5°±6.8° to 4.4°±2.6°; calcaneal pitch angle increased from 14.0°±3.3° to 18.6°±4.2°; calcaneal valgus angle decreased from 12.6°±7.3° to 4.3°±2.5°; and talonavicular coverage angle decreased from 20.9°±10.7° to 7.7°±5.2°. The up-mentioned parameters were all improved statistically significant at the last follow-up when compared with those before the operation (all P<0.05). Conclusion: H-LCL brings a significant improvement of clinical outcome scores and good radiological correction of flatfoot deformities in correcting flexible flatfoot, it conforms to the anatomical characteristics of the subtalar joint.

[Correlation analysis and benchmark dose study on bone metabolic biochemical index of low doses of exposed hydrogen fluoride workers]

Objective: To analyze correlation of occupational hydrogen fluoride exposure to low doses of bone metabolism index through occupational epidemiological investigation and benchmark dose calculation. Methods: In May 2021, using cluster sampling method, 237 workers exposed to hydrogen fluoride in a company were selected as the contact group, and 83 workers not exposed to hydrogen fluoride in an electronics production company were selected as the control group. The external exposure dose and urinary fluoride concentration, blood and urine biochemical indicators of the workers was measured.The relationship between external dose and internal dose of hydrogen fluoride was analyzed. The external dose, urinary fluoride was used as exposure biomarkers, while serum osteocalcin (BGP), serum alkaline phosphatase (AKP) and urinary hydroxyproline (HYP) were used as effect biomarkers for bone metabolism of hydrogen fluoride exposure. The benchmark dose calculation software (BMDS1.3.2) was used to calculate benchmark dose (BMD) . Results: Urine fluoride concentration in the contact group was correlated with creatinine-adjusted urine fluoride concentration (r=0.69, P=0.001). There was no significant correlation between the external dose of hydrogen fluoride and urine fluoride in the contact group (r=0.03, P=0.132). The concentrations of urine fluoride in the contact group and the control group were (0.81±0.61) and (0.45±0.14) mg/L, respectively, and the difference between the two groups was statistically significant (t=5.01, P=0.025). Using BGP, AKP and HYP as effect indexes, the urinary BMDL-05 values were 1.28, 1.47 and 1.08 mg/L, respectively. Conclusion: Urinary fluoride can sensitively reflect the changes in the effect indexes of biochemical indexes of bone metabolism. BGP and HYP can be used as early sensitive effect indexes of occupational hydrogen fluoride exposure.

The association between dietary selenium intake and Hashimoto's thyroiditis among US adults: National Health and Nutrition Examination Survey (NHANES), 2007-2012

BACKGROUND

Selenium has been shown to influence the pathological processes and physiological functions of thyroid. Although growing evidence has shown that selenium can improve the treatment of Hashimoto's thyroiditis (HT), there is a need to evaluate the association between dietary selenium intake and HT in a large cross-sectional study. This study explored the association between dietary selenium intake and HT based on the National Health reand Nutrition Examination Survey (NHANES) database (2007-2012).

METHODS

A total of 8756 of 30,442 participants were included in the study. Dietary selenium intake was the independent variable, while HT was the dependent variable. In addition, the relative importance of the selected variables was determined using the XGBoost model. A smooth curve was constructed based on the fully adjusted model to investigate the potential linear relationship between dietary selenium intake and HT. Smooth curves were also constructed to explore the linear/non-linear relationship between dietary selenium intake and thyroid peroxidase antibody (TPOAb)/ thyroglobulin antibody (TgAb).

RESULTS

The mean age of the enrolled participants was 44.35 years (± 20.92). The risk of HT was significantly reduced by a 35% per-unit increase in dietary selenium intake after fully adjusting for covariates according to the model (log2-transformed data; OR 0.65; 95% CI 0.51, 0.83). The XGBoost model revealed that dietary selenium intake was the most important variable associated with Hashimoto's thyroiditis. Dietary selenium intake (Log2-transformed) was negatively correlated with TPOAb levels [- 16.42 (- 22.18, - 10.65), P < 0.0001], while a non-linear relationship was observed between dietary selenium intake and TgAb with an inflection point of 6.58 (95.67 μg, Log2-transformed).

CONCLUSION

Dietary selenium intake is independently and inversely associated with HT risk. Moreover, dietary selenium intake is negatively correlated with TPOAb levels and non-linearly correlated with TGAb levels. Therefore, dietary selenium intake may be a safe and low-cost alternative for the prevention and treatment of HT.

Targeting PI4KA sensitizes refractory leukemia to chemotherapy by modulating the ERK/AMPK/OXPHOS axis

Background: The emergence of chemoresistance in leukemia markedly impedes chemotherapeutic efficacy and dictates poor prognosis. Recent evidence has revealed that phosphatidylinositol 4 kinase-IIIα (PI4KA) plays a critical role in tumorigenesis. However, the molecular mechanisms of PI4KA-regulated chemoresistance and leukemogenesis remain largely unknown.

Methods: Liquid chromatography-mass spectrometry (LC-MS), patient samples and leukemia xenograft mouse models were used to investigate whether PI4KA was an effective target to overcome chemoresistance in leukemia. Enzyme-linked immunosorbent assay (ELISA) and molecular mechanics/generalized born surface area (MM/GBSA) method were employed to identify cepharanthine (CEP) as a novel PI4KA inhibitor.

Results: High expression of PI4KA was observed in drug-resistant leukemia cells or in relapsed leukemia patients, which was correlated with poor overall survival. Depletion of PI4KA sensitized drug-resistant leukemia cells to chemotherapeutic drugs in vitro and in vivo by regulating ERK/AMPK/OXPHOS axis. We also identified cepharanthine (CEP) as a novel PI4KA inhibitor, which could undermine the stability of the PI4KA/TTC7/FAM126 complex, enhancing the sensitivity of drug-resistant leukemia cells to chemotherapeutic drugs in vitro and in vivo.

Conclusions: Our study underscored the potential of therapeutic targeting of PI4KA to overcome chemoresistance in leukemia. A combination of the PI4KA inhibitor with classic chemotherapeutic agents could represent a novel therapeutic strategy for the treatment of refractory leukemia.

[A multicenter epidemiological study of acute bacterial meningitis in children]

Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum β-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ²=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.

[Analysis of the effectiveness of coracoid osteotomy and concentric coaxial reconstruction of the glenoid cavity in the treatment of recurrent anterior dislocation of the shoulder joint]

Objective: To investigate the clinical efficacy of the modified Latarjet procedure in the treatment of recurrent anterior subluxation of the shoulder by "coaxial co-arc" reconstruction of the glenoid cavity. Methods: The clinical data of 103 cases (106 shoulders) of recurrent anterior dislocation of the shoulder admitted to the First Affiliated Hospital of the Army Military Medical University from January 2005 to December 2020 were retrospectively studied. Out of these cases, 84 were males and 19 were females; 31 with left-sided injuries while 75 with right-sided injuries, with a mean age of (29.4±11.5) years (16-61 years). The preoperative anterior fear test was positive, and a modified Latarjet procedure was used to reconstruct the shoulder glenoid defect through a "coaxial co-arc". The Rowe score, simple shoulder test (SST) score, and Visual analogue scale (VAS) score of pain were used to assess the shoulder's function. Parameters such as the postoperative shoulder recurrent dislocation rate, shoulder body external rotation angle, and subscapularis muscle strength changes were recorded postoperatively. Moreover, radiographs and CT scans were used to check for the incidence of osteoarthritis (Samson-Prieto score). Results: After a mean follow-up of 9.0 years (1 to 16 years), bony healing occurred 3 to 6 months postoperatively. The Rowe score improved from 40.4±6.5 preoperatively to 93.2±2.5 (P<0.001), the SST score improved from 5.2±1.3 preoperatively to 10.1±1.5 (P<0.001), and the VAS pain score decreased from 3.5±1.9 preoperatively to 1.1±1.2 (P<0.001) at the final follow-up. The angle of lateral external rotation of the shoulder joint was 58.8°±15.6° preoperatively and 57.6°±14.5° postoperatively with no statistically significant difference (P>0.05). There was no statistically significant difference in the measurement of subscapularis muscle strength between the healthy side and the affected side (P>0.05). In 89.6% of patients after surgery, coaxial co-arc reconstruction of the shoulder glenoid was obtained, and the shoulder glenoid defect and postoperative inclusion angle were significantly improved compared with those before surgery (P<0.001). Postoperatively, new-onset osteoarthritis developed in 7 cases (7/98), arthritis progressed in 2 cases (2/8), incisional healing was poor in 2 cases (2/98), and revision surgery was performed in 2 cases (2/98) due to bone mass detachment. Conclusion: Coracoid osteotomy and concentric coaxial reconstruction of the glenoid cavity elicits adequate good clinical efficacy for cases of recurrent anterior shoulder dislocation, with low recurrence rates, low revision rates and low incidence of osteoarthritis.

Follistatin-like 1 (FSTL1) interacts with Wnt ligands and Frizzled receptors to enhance Wnt/β-catenin signaling in obstructed kidneys in vivo

Follistatin (FS)-like 1 (FSTL1) is a member of the FS-SPARC (secreted protein, acidic and rich in cysteine) family of secreted and extracellular matrix proteins. The functions of FSTL1 have been studied in heart and lung injury as well as in wound healing; however, the role of FSTL1 in the kidney is largely unknown. Here, we show using single-cell RNA-Seq that Fstl1 was enriched in stromal cells in obstructed mouse kidneys. In addition, immunofluorescence demonstrated that FSTL1 expression was induced in fibroblasts during kidney fibrogenesis in mice and human patients. We demonstrate that FSTL1 overexpression increased renal fibrosis and activated the Wnt/β-catenin signaling pathway, known to promote kidney fibrosis, but not the transforming growth factor β (TGF-β), Notch, Hedgehog, or Yes-associated protein (YAP) signaling pathways in obstructed mouse kidneys, whereas inhibition of FSTL1 lowered Wnt/β-catenin signaling. Importantly, we show that FSTL1 interacted with Wnt ligands and the Frizzled (FZD) receptors but not the coreceptor lipoprotein receptor–related protein 6 (LRP6). Specifically, we found FSTL1 interacted with Wnt3a through its extracellular calcium–binding (EC) domain and von Willebrand factor type C–like (VWC) domain, and with FZD4 through its EC domain. Furthermore, we show that FSTL1 increased the association of Wnt3a with FZD4 and promoted Wnt/β-catenin signaling and fibrogenesis. The EC domain interacting with both Wnt3a and FZD4 also enhanced Wnt3a signaling. Therefore, we conclude that FSTL1 is a novel extracellular enhancer of the Wnt/β-catenin pathway.

Rational Remodeling of Atypical Scaffolds for the Design of Photoswitchable Cannabinoid Receptor Tools

Azobenzene-embedded photoswitchable ligands are the widely used chemical tools in photopharmacological studies. Current approaches to azobenzene introduction rely mainly on the isosteric replacement of typical azologable groups. However, atypical scaffolds may offer more opportunities for photoswitch remodeling, which are chemically in an overwhelming majority. Herein, we investigate the rational remodeling of atypical scaffolds for azobenzene introduction, as exemplified in the development of photoswitchable ligands for the cannabinoid receptor 2 (CB2). Based on the analysis of residue-type clusters surrounding the binding pocket, we conclude that among the three representative atypical arms of the CB2 antagonist, AM10257, the adamantyl arm is the most appropriate for azobenzene remodeling. The optimizing spacer length and attachment position revealed AzoLig 9 with excellent thermal bistability, decent photopharmacological switchability between its two configurations, and high subtype selectivity. This structure-guided approach gave new impetus in the extension of new chemical spaces for tool customization for increasingly diversified photo-pharmacological studies and beyond.

[LIM-domain binding protein 2 regulated by m6A modification inhibits lung adenocarcinoma cell proliferation in vitro]

OBJECTIVE

To investigate the role and expression pattern of LIM-domain binding protein 2 (LDB2) in lung adenocarcinoma.

OBJECTIVE

We studied the expression pattern of LDB2 in lung adenocarcinoma based on data from the online databases TCGA, GEO and CPTAC, and the results were verified in lung adenocarcinoma tissues and cells using immunohistochemistry, qRT-PCR and Western blotting. The relationship between LDB2 and the prognosis of patients with lung adenocarcinoma was analyzed using GEPIA and GEO databases. We further analyzed the role of LDB2 in regulating cell behaviors in a H1299 cell model over-expressing LDB2 using cell counting, soft agar colony forming assay and flow cytometry. The m⁶A binding sites on LDB2 were confirmed by bioinformatics analysis and MeRIP-qPCR assays. The effect of YTHDC2 on LDB2 was examined using qRT-PCR and Western blotting, and the binding of YTHDC2 to the transcript of LDB2 was verified with RIP-qPCR assays. Dual luciferase reporter assay was performed to verify YTHDC2 functioning via m⁶A sites.

OBJECTIVE

LDB2 expression was significantly decreased in lung adenocarcinoma in comparison with normal tissues based on data from TCGA, GEPIA and CPTAC, and the same results were obtained from 80 lung adenocarcinoma tissues and 17 adjacent normal tissues. Similarly, LDB2 expression was decreased in lung adenocarcinoma cells as compared with 16HBE cells. The data from Prognoscan and GEPIA suggested that a high LDB2 expression was positively correlated with a more favorable outcome of lung adenocarcinoma patients. LDB2-overexpressing H1299 cells showed a significant inhibition of proliferative activity with cell cycle arrest in S phage. Bioinformatics analysis and MeRIP-qPCR assay confirmed the presence of m⁶A sites on LDB2. The m⁶A reader YTHDC2 was positively related with LDB2 in lung adenocarcinoma based on data from GEPIA (r=0.22). Overexpression YTHDC2 significantly enhanced LDB2 expression in H1299 cells by about 19.35 folds. Dual luciferase reporter assay showed that YTHDC2 enhanced the promoter activity in the wild-type group but not in deletion group.

OBJECTIVE

LDB2 expression can be up-regulated by m⁶A reader YTHDC2 in lung adenocarcinoma to inhibit the proliferation of the tumor cells in vitro.

MiR-24 inhibits oligodendrocyte precursor cell differentiation after spinal injury by targeting adrenal medulla

OBJECTIVE

Oligodendrocyte precursor cells (OPCs) differentiate into oligodendrocytes (OLs) that provide nutrients to neurons. Adrenal medulla is (ADM) involved in nerve damage. MiR-24 participates in various diseases. However, the regulation and mechanism of miR-24 in oligodendrocyte precursor cell differentiation after spinal injury is unclear. MATERIALS  AND METHODS: Wistar rats were divided into sham operation group and model group. Real Time-PCR detects miR-24, PDGFRa and NG2 and MBP expression. OPC cells were cultured and divided into control group, miR-24 group, and si-miR-24 group followed by analysis of miR-24 expression by Real Time-PCR, expression of PDGFRa, NG2 and MBP by Western blot, as well as ADM content and secretion of IL-6 and TNF-α by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Expression of miR-24, PDGFRa, and NG2 was increased in the model group and MBP and ADM expression was decreased with increased secretion of IL-6 and TNF-α. Compared with control group, the difference was statistically significant (p<0.05). Upregulation of miR-24 promoted the expression of PDGFRa and NG2, decreased MBP and ADM level, and increased IL-6 and TNF-α secretion. Compared with control group, the difference was statistically significant (p<0.05). Downregulation of miR-24 reversed the above changes, and the difference was statistically significant (p<0.05).

CONCLUSIONS

MiR-24 expression is increased in spinal injury. Upregulation of miR-24 expression reduces adrenal medulla expression and inhibits oligodendrocyte precursor cell differentiation.

Chemopreventive effect of galangin against benzo(a)pyrene-induced stomach tumorigenesis through modulating aryl hydrocarbon receptor in Swiss albino mice

The present study was aimed to evaluate the chemopreventive potential of galangin against benzo(a)pyrene (BaP)-induced stomach carcinogenesis in Swiss albino mice. Stomach cancer was induced in experimental mice using BaP oral administration. The mice were treated with galangin (10 mg/kg b.wt.) before and during BaP administration. Oral administration of galangin at a dose of 10 mg/kg b.wt. significantly (p < 0.05) prevented the tumor incidence, tumor volume in the experimental animals. Further, galangin pretreatment prevents BaP-induced lipid peroxidation and restores BaP-mediated loss of cellular antioxidants status. It has also been found that galangin prevents BaP-induced activation of phase I detoxification enzymes. Furthermore, galangin pretreatment prevented the BaP-induced overexpression of cytochrome P450s isoform genes (CYP1A1, CYP1B1), aryl hydrocarbon receptor system (AhR, ARNT), transcriptional activators (CBP/p300, NF-kB), tumor growth factors, proto-oncogenes, invasion markers (TGFB, SRC-1, MYC, iNOS, MMP2, MMP9) and Phase II metabolic isoenzyme genes (GST) in the stomach tissue homogenate when compared to the control groups. The western blot results confirm that galangin (10 mg/kg. b.wt.) treatment significantly prevented the BaP-mediated expression of ArR, ARNT, and CYP1A1 proteins in the mouse stomach tissue. Therefore, the present results confirm that galangin prevents BaP-induced stomach carcinogenesis probably through modulating ArR and ARNT expression in the experimental mice.

Recent Advances and Challenges of the Drugs Acting on Monoamine Transporters

Background:

The human Monoamine Transporters (hMATs), primarily including hSERT, hNET and hDAT, are important targets for the treatment of depression and other behavioral disorders with more than the availability of 30 approved drugs.

Objective:

This paper is to review the recent progress in the binding mode and inhibitory mechanism of hMATs inhibitors with the central or allosteric binding sites, for the benefit of future hMATs inhibitor design and discovery. The Structure-Activity Relationship (SAR) and the selectivity for hit/lead compounds to hMATs that are evaluated by in vitro and in vivo experiments will be highlighted.

Methods:

PubMed and Web of Science databases were searched for protein-ligand interaction, novel inhibitors design and synthesis studies related to hMATs.

Results:

Literature data indicate that since the first crystal structure determinations of the homologous bacterial Leucine Transporter (LeuT) complexed with clomipramine, a sizable database of over 100 experimental structures or computational models has been accumulated that now defines a substantial degree of structural variability hMATs-ligands recognition. In the meanwhile, a number of novel hMATs inhibitors have been discovered by medicinal chemistry with significant help from computational models.

Conclusion:

The reported new compounds act on hMATs as well as the structures of the transporters complexed with diverse ligands by either experiment or computational modeling have shed light on the poly-pharmacology, multimodal and allosteric regulation of the drugs to transporters. All of the studies will greatly promote the Structure-Based Drug Design (SBDD) of structurally novel scaffolds with high activity and selectivity for hMATs.

Selective Inhibition of HDAC1 by Macrocyclic Polypeptide for the Treatment of Glioblastoma: A Binding Mechanistic Analysis Based on Molecular Dynamics

Glioblastoma (GBM) is the most common and aggressive intracranial malignant brain tumor, and the abnormal expression of HDAC1 is closely correlated to the progression, recurrence and metastasis of GBM cells, making selective inhibition of HDAC1 a promising strategy for GBM treatments. Among all available selective HDAC1 inhibitors, the macrocyclic peptides have gained great attention due to their remarkable inhibitory selectivity on HDAC1. However, the binding mechanism underlying this selectivity is still elusive, which increases the difficulty of designing and synthesizing the macrocyclic peptide-based anti-GBM drug. Herein, multiple computational approaches were employed to explore the binding behaviors of a typical macrocyclic peptide FK228 in both HDAC1 and HDAC6. Starting from the docking conformations of FK228 in the binding pockets of HDAC1&6, relatively long MD simulation (500 ns) shown that the hydrophobic interaction and hydrogen bonding of E91 and D92 in the Loop2 of HDAC1 with the Cap had a certain traction effect on FK228, and the sub-pocket formed by Loop1 and Loop2 in HDAC1 could better accommodate the Cap group, which had a positive effect on maintaining the active conformation of FK228. While the weakening of the interactions between FK228 and the residues in the Loop2 of HDAC6 during the MD simulation led to the large deflection of FK228 in the binding site, which also resulted in the decrease in the interactions between the Linker region of FK228 and the previously identified key amino acids (H134, F143, H174, and F203). Therefore, the residues located in Loop1 and Loop2 contributed in maintaining the active conformation of FK228, which would provide valuable hints for the discovery and design of novel macrocyclic polypeptide HDAC inhibitors.

The binding mode of vilazodone in the human serotonin transporter elucidated by ligand docking and molecular dynamics simulations

Vilazodone is a novel antidepressant used for the treatment of major depressive disorder (MDD) with a primary action mechanism of inhibiting the human serotonin reuptake transporter (hSERT) and acting as a 5-HT_1A receptor partial agonist. The interaction between vilazodone and the 5-HT_1A receptor has been reported, however, the binding mode of vilazodone in the hSERT remains elusive. In the current study, to elucidate the molecular mechanism of vilazodone binding in the hSERT, the drug and its five analogs were docked into the hSERT crystal structure as initial conformations and were sampled by 400 ns molecular dynamics (MD) simulations. Through the analysis of the profiles of protein-ligand binding free energies, interaction fingerprints, and conformational rearrangements, the binding mode of vilazodone in the hSERT was revealed. As a result, unlike the classical antidepressants located in the S1 site of the hSERT, vilazodone adopted a linear pose in the binding pocket. Its arylpiperazine fragment occupies the central site (S1) and interacts with Y95, D98, I172, Y176, F335, F341, S438, and T439, while the indole fragment extends to the allosteric site (S2) via interacting with the ionic switch (R104/E403) between the two sites. The new insights obtained are not only helpful in understanding the binding mode of vilazodone in the hSERT, but also provide valuable guidance to the discovery of novel antidepressant drugs.

Influence of family history on risk of second primary cancers and survival in patients with squamous cell skin cancer

BACKGROUND

Patients with squamous cell skin cancer (SCC) have an excellent prognosis but second primary cancers (SPCs) weaken survival prospects. Family history is a known risk factor for cancer but whether it is a risk factor for SPC in patients with SCC is not known.

OBJECTIVES

To quantify the risk of family history on SPCs in patients with SCC and estimate survival probabilities of patients with SPCs depending on family history.

METHODS

With 13 945 histologically verified SCCs, relative risks (RRs) were estimated for family history using a generalized regression model. For survival analysis, hazard ratios (HRs) were assessed using a multivariable Cox proportional-hazards model.

RESULTS

Family history of invasive SCC increased risk of second invasive SCC [RR = 42·92, 95% confidence interval (CI) 33·69-50·32] compared with risk without family history (RR 19·12, 95% CI 17·88-21·08). Family history of any nonskin cancer in invasive SCC increased risk of the same cancers to be diagnosed as SPC (RRF_H = 1·48, 95% CI 1·35-1·61 vs. RR_{no FH} = 1·40, 95% CI 1·32-1·48); significant increases were observed for seven different nonskin cancers. Most results were replicated for in situ SCC. SPC was deleterious for survival irrespective of family history; HR for patients with SPC was 4·28 (95% CI 3·83-4·72) vs. those without SPC (1·04).

CONCLUSIONS

Family history of nonskin cancer was associated with approximately a doubling of risk for SPCs in patients with SCC. SPC increases the death rate in patients with SCC 3-4 times, irrespective of family history. Taking family history into account at SCC diagnosis may help prevention or early detection of SPCs. What's already known about this topic? Second primary cancers (SPCs) are frequently diagnosed in patients with invasive and in situ squamous cell carcinoma (SCC); some epidemiological studies suggest a link to immune dysfunction. Family history of cancer is a risk factor for practically all first primary cancers but whether it also influences risk of SPCs in patients with SCC is not known. The possible influence of family history on survival in patients with SCC remains to be established. Linked Comment: Youlden and Baade. Br J Dermatol 2020; 183:414-415.

Proof of concept: hip joint damage occurs at the zone of femoroacetabular impingement (FAI) in an experimental FAI sheep model

OBJECTIVE

In ovine hips chondrolabral damage as seen in cam-type femoroacetabular impingement (FAI) can be induced via an intertrochanteric varus osteotomy. However, it is yet to proven whether the observed cartilage damage is caused by a dynamic cam type impingement. Thus we asked, (1) whether actual cartilage damage observed after FAI induction in ovine hips occurs at the predicted, computed zone of FAI; (2) whether the extent of cartilage damage increases with ambulation time in this animal model?

DESIGN

In this experimental, controlled, comparative study 20 sheep underwent unilateral FAI induction through an intertrochanteric varus osteotomy. Preoperatively sheep underwent computed tomography to generate three-dimensional models of the osseous pelvis and femur. The models were used to predict impingement zones before and after simulated varus osteotomy using range of motion (ROM) analysis. Sheep were sacrificed after 14-40 weeks of ambulation. At sacrifice cartilage was inspected and (1) location of actual damage and computed impingement zones were compared; (2) Cartilage damage was compared between short- and long ambulation groups.

RESULTS

(1) The average location and the extent of peripheral and central cartilage lesions did not differ with the computed impingement zones (all P > 0.05). (2) Grades of central, posterior cartilage damage were more severe in the long-compared to the short ambulation group (2.2 ± 1.8 vs 0.4 ± 0.5; P = 0.030).

CONCLUSIONS

In this experimental ovine FAI model the surgical induction of an osseous impingement conflict between the femur and acetabulum causes cartilage damage at the zone of simulated FAI.

Liver kinase B1 suppresses the metastasis and angiogenesis of lung cancer: involvement of the Shh signaling pathway

Liver kinase B1 (LKB1) is revealed to have a close relationship with cancers. However, the underlying mechanism remains unclear. This study aimed to reveal the mechanism through which LKB1 performed its role in lung cancer. LKB1 shRNA and overexpression plasmid were employed to investigate the role of LKB1 in lung cancer in vitro and in vivo. The involvement of Shh signaling pathway was assessed by western blot. Silence of LKB1 promoted, while overexpression of LKB1 inhibited the migration, invasion and angiogenesis of lung cancer cells. Further study showed that Shh signaling pathway was suppressed by LKB1. Cyclopamine, a Shh signaling pathway inhibitor, reduced the effects of LKB1 silence, indicating that LKB1 inhibits the migration, invasion and angiogenesis through suppressing the Shh signaling pathway. In vivo study also showed that Shh signaling pathway was involved in the modulation of LKB1 on the metastasis and angiogenesis of lung cancer. Our study demonstrates that LKB1 inhibits the metastasis and angiogenesis of lung cancer through suppressing the Shh signaling pathway.

Implication of lymph node staging in migration and different treatment strategies for stage T2N0M0 and T1N1M0 resected gastric cancer: a SEER population analysis

PURPOSE

The purpose of this study was to explore the differences between stage T2N0M0 and stage T1N1M0 gastric cancer (GC) and to identify the necessity of adjuvant treatment (AT) for these stages.

METHODS

Between years 2004 and 2015, 1971 stage IB GC patients who underwent radical surgery were recruited using the Surveillance, Epidemiology and End Results database. We conducted univariate/multivariate analyses, the propensity score matching and evaluated gastric cancer-specific survival (GCSS) and overall survival (OS) with the log-rank test.

RESULTS

T1N1M0 had a significantly worse survival than T2N0M0 in both GCSS and OS before and after the propensity score matching. Examined lymph nodes (ELN) ≤ 15 and T1N1M0 were independent risk factors for worse GCSS and OS in stage IB GC. The absence of adjuvant chemotherapy (CT) was an independent risk factor for worse GCSS and OS in T1N1M0 but not in T2N0M0. AT demonstrated similar GCSS and OS with surgery alone (SA) for T2N0M0 but better survival for T1N1M0. Compared to CT and adjuvant chemoradiotherapy (CRT) group, SA demonstrated significantly worse GCSS and OS for T1N1M0. There was no significant difference between CT and CRT in both T2N0M0 and T1N1M0 stages. T2N0M0 had a better survival than T1N1M0 in ELN ≤ 15 subgroup. However, similar survival was demonstrated in ELN > 15 subgroup.

CONCLUSIONS

T2N0M0 GC has a better survival rate than T1N1M0 GC when ELN are ≤ 15. Moreover, T2N0M0 GC may not benefit from AT. T1N1M0 GC requires CT but not adjuvant radiotherapy.

Prediction of the binding mode and resistance profile for a dual-target pyrrolyl diketo acid scaffold against HIV-1 integrase and reverse-transcriptase-associated ribonuclease H

The rapid emergence of drug-resistant variants is one of the most common causes of highly active antiretroviral therapeutic (HAART) failure in patients infected with HIV-1. Compared with the existing HAART, the recently developed pyrrolyl diketo acid scaffold targeting both HIV-1 integrase (IN) and reverse transcriptase-associated ribonuclease H (RNase H) is an efficient approach to counteract the failure of anti-HIV treatment due to drug resistance. However, the binding mode and potential resistance profile of these inhibitors with important mechanistic principles remain poorly understood. To address this issue, an integrated computational method was employed to investigate the binding mode of inhibitor JMC6F with HIV-1 IN and RNase H. By using per-residue binding free energy decomposition analysis, the following residues: Asp64, Thr66, Leu68, Asp116, Tyr143, Gln148 and Glu152 in IN, Asp443, Glu478, Trp536, Lys541 and Asp549 in RNase H were identified as key residues for JMC6F binding. And then computational alanine scanning was carried to further verify the key residues. Moreover, the resistance profile of the currently known major mutations in HIV-1 IN and 2 mutations in RNase H against JMC6F was predicted by in silico mutagenesis studies. The results demonstrated that only three mutations in HIV-1 IN (Y143C, Q148R and N155H) and two mutations in HIV-1 RNase H (Y501R and Y501W) resulted in a reduction of JMC6F potency, thus indicating their potential role in providing resistance to JMC6F. These data provided important insights into the binding mode and resistance profile of the inhibitors with a pyrrolyl diketo acid scaffold in HIV-1 IN and RNase H, which would be helpful for the development of more effective dual HIV-1 IN and RNase H inhibitors.

Exploring the Binding Mechanism of Metabotropic Glutamate Receptor 5 Negative Allosteric Modulators in Clinical Trials by Molecular Dynamics Simulations

Metabotropic glutamate receptor 5 (mGlu₅) plays a key role in synaptic information storage and memory, which is a well-known target for a variety of psychiatric and neurodegenerative disorders. In recent years, the increasing efforts have been focused on the design of allosteric modulators, and the negative allosteric modulators (NAMs) are the front-runners. Recently, the architecture of the transmembrane (TM) domain of mGlu₅ receptor has been determined by crystallographic experiment. However, it has been not well understood how the pharmacophores of NAMs accommodated into the allosteric binding site. In this study, molecular dynamics (MD) simulations were performed on mGlu₅ receptor bound with NAMs in preclinical or clinical development to shed light on this issue. In order to identify the key residues, the binding free energies as well as per-residue contributions for NAMs binding to mGlu₅ receptor were calculated. Subsequently, the in silico site-directed mutagenesis of the key residues was performed to verify the accuracy of simulation models. As a result, the shared common features of the studied 5 clinically important NAMs (mavoglurant, dipraglurant, basimglurant, STX107, and fenobam) interacting with 11 residues in allosteric site were obtained. This comprehensive study presented a better understanding of mGlu₅ receptor NAMs binding mechanism, which would be further used as a useful framework to assess and discover novel lead scaffolds for NAMs.

What Contributes to Serotonin-Norepinephrine Reuptake Inhibitors' Dual-Targeting Mechanism? The Key Role of Transmembrane Domain 6 in Human Serotonin and Norepinephrine Transporters Revealed by Molecular Dynamics Simulation

Dual inhibition of serotonin and norepinephrine transporters (hSERT and hNET) gives greatly improved efficacy and tolerability for treating major depressive disorder (MDD) compared with selective reuptake inhibitors. Pioneer studies provided valuable information on structure, function, and pharmacology of drugs targeting both hSERT and hNET (serotonin-norepinephrine reuptake inhibitors, SNRIs), and the differential binding mechanism between SNRIs and selective inhibitors of 5-HT (SSRIs) or NE (sNRIs) to their corresponding targets was expected to be able to facilitate the discovery of a privileged drug-like scaffold with improved efficacy. However, the dual-target mechanism of SNRIs was still elusive, and the binding mode distinguishing SNRIs from SSRIs and sNRIs was also unclear. Herein, an integrated computational strategy was adopted to discover the binding mode shared by all FDA approved SNRIs. The comparative analysis of binding free energy at the per-residue level discovered that residues Phe335, Leu337, Gly338, and Val343 located at the transmembrane domain 6 (TM6) of hSERT (the corresponding residues Phe317, Leu319, Gly320, and Val325 in hNET) were the determinants accounting for SNRIs' dual-acting inhibition, while residues lining TM3 and 8 (Ile172, Ser438, Thr439, and Leu443 in hSERT; Val148, Ser419, Ser420, and Met424 in hNET) contributed less to the binding of SNRIs than that of SSRIs and sNRIs. Based on these results, the distances between an SNRI's centroid and the centroids of its two aromatic rings (measuring the depth of rings stretching into hydrophobic pockets) were discovered as the key to the SNRIs' dual-targeting mechanism. This finding revealed SNRIs' binding mechanism at an atomistic level, which could be further utilized as structural blueprints for the rational design of privileged drug-like scaffolds treating MDD.

A novel diagnostic algorithm for heparin-induced thrombocytopenia

INTRODUCTION

While diagnostic algorithm using PF4-heparin enzyme-linked immunosorbent assay (ELISA) optical density (OD), and heparin neutralization assay (HNA), or 4T score have been proposed to replace serotonin-release assay (SRA) for heparin-induced thrombocytopenia (HIT), their performance against SRA is unclear. In this study, we proposed and validated the performance of a new algorithm combining PF4-heparin ELISA optical density (OD), HNA and 4T score against SRA for HIT diagnosis.

METHODS

Heparin neutralization assays were performed on specimens submitted for HIT testing with positive PF4-heparin ELISA from December 2015 to September 2017, which were separated into a "training" and a "validation" data set. 4T scores were calculated for ELISA positive cases.

RESULTS

A total of 123 consecutive unique patient samples had positive PF4-heparin ELISA with also HNA data, SRA data, and 4T scores available. Compared to SRA, a "laboratory criteria" (ELISA OD ≥ 1.4 and HNA ≥ 70%) had a sensitivity of 88% (14/16) and specificity of 91% (42/46), and a "combined criteria" (4T score = 8, or 4T score = 6 or 7 and ELISA OD ≥ 1.0, or 4T score = 4 or 5 and ELISA OD ≥ 2.0) had a sensitivity of 75% (12/16) and specificity of 98% (45/46) in the training data set. Laboratory and combined criteria had 90% (56/62) concordance rate. Importantly, for these concordant cases, the diagnostic specificity is 100% (46/46). Based on the data, a novel diagnostic algorithm combining these 2 criteria was proposed and validated prospectively.

CONCLUSION

A novel algorithm has high diagnostic accuracy and potentially could eliminate the need for SRA testing in at least 90% patients with suspected HIT.

Pharmacokinetics of cefquinome in crucian carp (Carassius auratus gibelio) after oral, intramuscular, intraperitoneal, and bath administration

The pharmacokinetics (PK) of cefquinome (CEQ) was studied in crucian carp (Carassius auratus gibelio) after single oral, intramuscular (i.m.), and intraperitoneal (i.p.) administration at a dose of 10 mg/kg body weight and following incubation in a 5 mg/L bath for 5 hr at 25°C. The plasma concentration of CEQ was determined using high-performance liquid chromatography (HPLC). PK parameters were calculated based on mean CEQ concentration using WinNonlin 6.1 software. The disposition of CEQ following oral, i.m., or i.p. administration was best described by a two-compartment open model with first-order absorption. After oral, i.m., and i.p. administration, the maximum plasma concentration (C_max ) values were 1.52, 40.53, and 67.87 μg/ml obtained at 0.25, 0.23, and 0.35 hr, respectively, while the elimination half-life (T_1/2β ) values were 4.68, 7.39, and 6.88 hr, respectively; the area under the concentration-time curve (AUC) values were 8.61, 339.11, and 495.06 μg hr/ml, respectively. No CEQ was detected in the plasma after bath incubation. Therapeutic blood concentrations of CEQ can be achieved in the crucian carp following i.m. and i.p. administration at a dosage of 10 mg/kg once every 2 days.

Advancing porphyrin's biomedical utility via supramolecular chemistry

Porphyrins are organic heterocyclic macrocycles with photophysical properties well-suited for clinical phototherapy and cancer imaging. However, their wider application in the clinical management of disease is barred by poor aqueous solubility, bioavailability, tumour accumulation and skin phototoxicity. These limitations instigated the development of supramolecular platforms that improved porphyrin pharmacokinetics and tumour-homing. The supramolecular formulation of porphyrins also facilitates single agent-mediated deeper tissue photoactivation, extended imaging and theranostic multimodality, and synergistic application of multiple therapies. Supramolecular porphyrin structures can overcome additional limitations of porphyrin-mediated photodynamic therapy (PDT), including low depths of tissue penetration that restrict PDT to superficial lesions, inability to treat hypoxic tumours, and incomplete tumour damage. In this review, we discuss the photophysical properties of porphyrins, and overview the clinically-relevant advantages and challenges arising from their incorporation within supramolecular platforms. Specifically, fundamentals underlying the ability of these platforms to ameliorate passive and active porphyrin delivery to tumours, achieve deeper tissue PDT via red-shifted porphyrin Q-bands, energy transfer and sonodynamic effects, and enable new porphyrin-mediated theranostics and synergistic therapeutic capabilities will be explained and exemplified with seminal and cutting-edge in vivo studies.

Revealing vilazodone's binding mechanism underlying its partial agonism to the 5-HT1A receptor in the treatment of major depressive disorder

It has been estimated that major depressive disorder (MDD) will become the second largest global burden among all diseases by 2030. Various types of drugs, including selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and serotonin receptor partial agonist/reuptake inhibitors (SPARIs), have been approved and become the primary or first-line medications prescribed for MDD. SPARI was expected to demonstrate more enhanced drug efficacy and a rapid onset of action as compared to SSRI and SNRI. As one of the most famous SPARIs, vilazodone was approved by the FDA for the treatment of MDD. Because of the great clinical importance of vilazodone, its binding mechanism underlying its partial agonism to the 5-HT_1A receptor (5-HT_1AR) could provide valuable information to SPARIs' drug-like properties. However, this mechanism has not been reported to date; consequently, the rational design of new efficacious SPARI-based MDD drugs is severely hampered. To explore the molecular mechanism of vilazodone, an integrated computational strategy was adopted in this study to reveal its binding mechanism and prospective structural feature at the agonist binding site of 5-HT_1AR. As a result, 22 residues of this receptor were identified as hotspots, consistently favoring the binding of vilazodone and its analogues, and a common binding mechanism underlying their partial agonism to 5-HT_1AR was, therefore, discovered. Moreover, three main interaction features between vilazodone and 5-HT_1AR have been revealed and schematically summarized. In summary, this newly identified binding mechanism will provide valuable information for medicinal chemists working in the field of rational design of novel SPARIs for MDD treatment.

Strong spin-photon coupling in silicon

Long coherence times of single spins in silicon quantum dots make these systems highly attractive for quantum computation, but how to scale up spin qubit systems remains an open question. As a first step to address this issue, we demonstrate the strong coupling of a single electron spin and a single microwave photon. The electron spin is trapped in a silicon double quantum dot, and the microwave photon is stored in an on-chip high-impedance superconducting resonator. The electric field component of the cavity photon couples directly to the charge dipole of the electron in the double dot, and indirectly to the electron spin, through a strong local magnetic field gradient from a nearby micromagnet. Our results provide a route to realizing large networks of quantum dot-based spin qubit registers.

Computational identification of the binding mechanism of a triple reuptake inhibitor amitifadine for the treatment of major depressive disorder

A shared binding mode involving eleven key residues at the S1 site of MATs for the binding of amitifadine is identified.

Computational characterization of the selective inhibition of human norepinephrine and serotonin transporters by an escitalopram scaffold

Selective inhibition of human norepinephrine and serotonin transporters has been studied by computational approaches. 4 warm spots in hNET and 4 in hSERT were found to exert a pronounced effect on inhibition by the studied ligands.

Differentiating physicochemical properties between NDRIs and sNRIs clinically important for the treatment of ADHD

BACKGROUND

Drugs available for treating attention-deficit hyperactivity disorder (ADHD) are mainly selective norepinephrine (sNRIs) and dual norepinephrine-dopamine (NDRIs) reuptake inhibitors. The major problem of sNRIs lines in their delayed onset of action and partial- or non-responses, which makes NDRIs distinguished in drug efficacy. Understanding of the differential binding modes of these 2 types of drugs to their corresponding targets can give great insights into the discovery of privileged drug-like scaffolds with improved efficacy. So far, no such study has been carried out.

METHODS

A combinatorial computational strategy, integrating homology modeling, molecular docking, molecular dynamics (MD) and binding free energy calculation, was employed to analyze the binding modes of 8 clinically important ADHD drugs in their targets.

RESULTS

Binding modes of 2 types of ADHD drugs (sNRIs and NDRIs) in their targets was identified for the first time by MD simulation, and 15 hot spot residues were discovered as crucial for NDRIs' binding in hNET and hDAT. Comparing to sNRIs, a clear reduction in the hydrophobic property of NDRIs' one functional group was observed, and the depth of drugs' aromatic ring stretched into the pocket of both targets was further identified as key contributors to drugs' selectivity.

CONCLUSIONS

The hydrophobic property of NDRI ADHD drugs' one functional group contributes to their selectivity when bind hNET and hDAT.

GENERAL SIGNIFICANCE

These results provide insights into NDRI ADHD drugs' binding mechanisms, which could be utilized as structural blueprints for assessing and discovering more efficacious drugs for ADHD therapy.

Correction: Tailored theranostic apolipoprotein E3 porphyrin-lipid nanoparticles target glioblastoma

Correction for ‘Tailored theranostic apolipoprotein E3 porphyrin-lipid nanoparticles target glioblastoma’ by M. A. Rajora et al., Chem. Sci., 2017, DOI: ; 10.1039/c7sc00732a.

Pharmacokinetics of enrofloxacin after oral, intramuscular and bath administration in crucian carp (Carassius auratus gibelio)

The pharmacokinetics of enrofloxacin (ENR) was studied in crucian carp (Carassius auratus gibelio) after single administration by intramuscular (IM) injection and oral gavage (PO) at a dose of 10 mg/kg body weight and by 5 mg/L bath for 5 hr at 25°C. The plasma concentrations of ENR and ciprofloxacin (CIP) were determined by HPLC. Pharmacokinetic parameters were calculated based on mean ENR or CIP concentrations using WinNonlin 6.1 software. After IM, PO and bath administration, the maximum plasma concentration (C_max ) of 2.29, 3.24 and 0.36 μg/ml was obtained at 4.08, 0.68 and 0 hr, respectively; the elimination half-life (T_1/2β ) was 80.95, 62.17 and 61.15 hr, respectively; the area under the concentration-time curve (AUC) values were 223.46, 162.72 and 14.91 μg hr/ml, respectively. CIP, an active metabolite of enrofloxacin, was detected and measured after all methods of drug administration except bath. It is possible and practical to obtain therapeutic blood concentrations of enrofloxacin in the crucian carp using IM, PO and bath immersion administration.