Unraveling the mechanisms of NK cell dysfunction in aging and Alzheimer's disease: insights from GWAS and single-cell transcriptomics.

Background: Aging is an important factor in the development of Alzheimer's disease (AD). The senescent cells can be recognized and removed by NK cells. However, NK cell function is gradually inactivated with age. Therefore, this study used senescence as an entry point to investigate how NK cells affect AD. Methods: The study validated the correlation between cognition and aging through a prospective cohort of the National Health and Nutrition Examination Survey database. A cellular trajectory analysis of the aging population was performed using single-cell nuclear transcriptome sequencing data from patients with AD and different ages. The genome-wide association study (GWAS) cohort of AD patients was used as the outcome event, and the expression quantitative trait locus was used as an instrumental variable. Causal associations between genes and AD were analyzed by bidirectional Mendelian randomization (MR) and co-localization. Finally, clinical cohorts were constructed to validate the expression of key genes. Results: A correlation between cognition and aging was demonstrated using 2,171 older adults over 60 years of age. Gene regulation analysis revealed that most of the highly active transcription factors were concentrated in the NK cell subpopulation of AD. NK cell trajectories were constructed for different age populations. MR and co-localization analyses revealed that CHD6 may be one of the factors influencing AD. Conclusion: We explored different levels of AD and aging from population cohorts, single-cell data, and GWAS cohorts and found that there may be some correlations of NK cells between aging and AD. It also provides some basis for potential causation.

Machine learning and experimental validation identified autophagy signature in hepatic fibrosis.

Background: The molecular mechanisms of hepatic fibrosis (HF), closely related to autophagy, remain unclear. This study aimed to investigate autophagy characteristics in HF. Methods: Gene expression profiles (GSE6764, GSE49541 and GSE84044) were downloaded, normalized, and merged. Autophagy-related differentially expressed genes (ARDEGs) were determined using the limma R package and the Wilcoxon rank sum test and then analyzed by GO, KEGG, GSEA and GSVA. The infiltration of immune cells, molecular subtypes and immune types of healthy control (HC) and HF were analyzed. Machine learning was carried out with two methods, by which, core genes were obtained. Models of liver fibrosis in vivo and in vitro were constructed to verify the expression of core genes and corresponding immune cells. Results: A total of 69 ARDEGs were identified. Series functional cluster analysis showed that ARDEGs were significantly enriched in autophagy and immunity. Activated CD4 T cells, CD56bright natural killer cells, CD56dim natural killer cells, eosinophils, macrophages, mast cells, neutrophils, and type 17 T helper (Th17) cells showed significant differences in infiltration between HC and HF groups. Among ARDEGs, three core genes were identified, that were ATG5, RB1CC1, and PARK2. Considerable changes in the infiltration of immune cells were observed at different expression levels of the three core genes, among which the expression of RB1CC1 was significantly associated with the infiltration of macrophage, Th17 cell, natural killer cell and CD56dim natural killer cell. In the mouse liver fibrosis experiment, ATG5, RB1CC1, and PARK2 were at higher levels in HF group than those in HC group. Compared with HC group, HF group showed low positive area in F4/80, IL-17 and CD56, indicating decreased expression of macrophage, Th17 cell, natural killer cell and CD56dim natural killer cell. Meanwhile, knocking down RB1CC1 was found to inhibit the activation of hepatic stellate cells and alleviate liver fibrosis. Conclusion: ATG5, RB1CC1, and PARK2 are promising autophagy-related therapeutic biomarkers for HF. This is the first study to identify RB1CC1 in HF, which may promote the progression of liver fibrosis by regulating macrophage, Th17 cell, natural killer cell and CD56dim natural killer cell.

Isovitexin alleviates hepatic fibrosis by regulating miR-21-mediated PI3K/Akt signaling and glutathione metabolic pathway: based on transcriptomics and metabolomics.

BACKGROUND: Effective drugs for the treatment of hepatic fibrosis have not yet been identified. Isovitexin (IVT) is a promising hepatoprotective agent owing to its efficacy against acute liver injury. However, the role of IVT in liver fibrosis has not been reported. PURPOSE: To explore the effect of IVT on liver fibrosis both in vitro and in vivo. STUDY DESIGN AND METHODS: A mouse model of liver fibrosis induced by carbon tetrachloride (CCl4) and two types of hepatic stellate cell models induced by platelet-derived growth factor-BB (PDGF-BB) were established to evaluate the effect of IVT on hepatic fibrosis. Transcriptomics and metabolomics were used to predict the underlying targets of IVT and were validated by a combination of in vitro and in vivo experiments. Exploration of miRNA and N6-methyladenosine (m6A) modifications was also carried out to detect the key upstream targets of the above targets. RESULTS: IVT reduced collagen deposition and hepatic stellate cell activation to alleviate liver fibrosis. The transcriptomics and metabolomics analyses showed that phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling and the glutathione (GSH) metabolic pathway may be the main regulatory processes of IVT in hepatic fibrosis. Both the in vitro and in vivo experiments confirmed the inhibitory effect of IVT on the PTEN-PI3K-Akt-mTOR axis and activation of the GSH metabolic pathway. A miR-21 mimic inhibited the effects of IVT on these two pathways, suggesting that miR-21 is the hub for IVT regulation of PI3K-Akt signaling and the GSH metabolic pathway. IVT also increased pri-miR-21 level and reduced the m6A enrichment of pri-miR-21, demonstrating that IVT may regulate pri-miR-21 through m6A modification, thereby affecting the maturation of miR-21. CONCLUSION: This study is the first to propose a protective effect of IVT against liver fibrosis. The mechanism of IVT against hepatic fibrosis is based on the regulation of miR-21, targeting PTEN-Akt signaling and the GSH metabolic pathway, which is also a novel discovery.

Asiatic acid ameliorates rifampicin- and isoniazid-induced liver injury in vivo by regulating sphingolipid metabolism and mitogen-activated protein kinase signalling pathways.

In this study, we aimed to determine whether asiatic acid (AA) exerts any therapeutic effects on rifampicin (RFP)- and isoniazid (INH)-induced liver injury and elucidate the underlying mechanisms. Briefly, liver injury in mice was induced via RFP and INH administration. We investigated the effects and potential action mechanisms of AA on liver injury using transcriptomics, metabolomics and various examinations. We found that AA significantly ameliorated the pathological changes in liver tissues and decreased the transaminase activity, inflammation and oxidative stress damage. Transcriptomics revealed 147 differentially expressed genes (DEGs) between the AA and model groups that were enriched in metabolic and mitogen-activated protein kinase (MAPK) signalling pathways. Metabolomics revealed 778 differentially expressed metabolites between the AA and model groups. Furthermore, integrated transcriptomics and metabolomics analyses revealed strong correlations between DEGs and differentially expressed metabolites and indicated that AA regulates the sphingolipid metabolism by inhibiting the expression of delta 4-desaturase, sphingolipid 1. Experimental results confirmed that AA inhibited the MAPK signalling pathway. In summary, AA inhibits inflammation and oxidative stress damage by regulating the sphingolipid metabolism pathway and blocking the MAPK signalling pathway, thereby relieving the RFP/INH-induced liver injury.

Association of a Novel DOCK2 Mutation-Related Gene Signature With Immune in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a malignant tumor with high morbidity and mortality worldwide. Many studies have shown that dedicator of cytokinesis 2 (DOCK2) has a crucial role as a prognostic factor in various cancers. However, the potentiality of DOCK2 in the diagnosis of HCC has not been fully elucidated. In this work, we aimed to investigate the prognostic role of DOCK2 mutation in HCC. The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) cohorts were utilized to identify the mutation frequency of DOCK2. Then, univariate Cox proportional hazard regression analysis, random forest (RF), and multivariate Cox regression analysis were performed to develop the risk score that was significantly related to DOCK2 mutation. Moreover, Gene Set Enrichment Analysis (GSEA), Gene Set Variation Analysis (GSVA), and immune correlation analysis were conducted for an in-depth study of the biological process of DOCK2 mutation involved in HCC. The results revealed that the mutation frequency of DOCK2 was relatively higher than that in non-cancer control subjects, and patients with DOCK2 mutations had a low survival rate and a poor prognosis compared with the DOCK2-wild group. In addition, the secretin receptor (SCTR), tetratricopeptide repeat, ankyrin repeat and coiled-coil domain-containing 1 (TANC1), Alkb homolog 7 (ALKBH7), FRAS1-related extracellular matrix 2 (FREM2), and G protein subunit gamma 4 (GNG4) were found to be the most relevant prognostic genes of DOCK2 mutation, and the risk score based on the five genes played an excellent role in predicting the status of survival, tumor mutation burden (TMB), and microsatellite instability (MSI) in DOCK2 mutant patients. In addition, DOCK2 mutation and the risk score were closely related to immune responses. In conclusion, the present study identifies a novel prognostic signature in light of DOCK2 mutation-related genes that shows great prognostic value in HCC patients; and this gene mutation might promote tumor progression by influencing immune responses. These data may provide valuable insights for future investigations into personalized forecasting methods and also shed light on stratified precision oncology treatment.

The Integrated Analysis of Transcriptomics and Metabolomics Unveils the Therapeutical Effect of Asiatic Acid on Alcoholic Hepatitis in Rats.

The present study was to investigate the therapeutical effects and mechanisms of Asiatic acid from Potentilla chinensis against alcoholic hepatitis. Rats were intragastrically fed with alcohol for 12 weeks to induce alcoholic hepatitis and then treated with various drugs for further 12 weeks. The results showed that Asiatic acid significantly alleviated liver injury caused by alcohol in rats, as evidenced by the improved histological changes and the lower levels of AST, ALT, and TBIL. Besides, Asiatic acid significantly enhanced the activity of ADH and ALDH, promoting alcohol metabolism. Asiatic acid suppressed CYP2E1 activity and NADP+/NADPH ratio, resulting in low ROS production. Further study revealed that Asiatic acid markedly reduced hepatocyte apoptosis by regulating the expression levels of apoptosis-related protein. Moreover, Asiatic acid could regulate the Nrf2 and NF-κB signaling pathway, attenuating oxidative stress and inflammation as a result. Interestingly, the comprehensive analysis of transcriptomics and metabolomics indicated that Asiatic acid inhibited the gene expression of Gpat3 and thereby affected the biosynthesis of the metabolites (1-acyl-Sn-glycerol-3-phosphocholine, phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine), regulating the glycerophospholipid metabolism pathway and ultimately ameliorating hepatocyte damage. In conclusion, this study demonstrates that Asiatic acid can ameliorate alcoholic hepatitis by modulating the NF-κB and Nrf2 signaling pathways and the glycerophospholipid metabolism pathway, which may be developed as a potential medicine for the treatment of alcoholic hepatitis.

Isovitexin protects against acute liver injury by targeting PTEN, PI3K and BiP via modification of m6A.

Isovitexin (IVT) has been shown to have a potential therapeutic effect on acute liver injury (ALI), but its underlying mechanisms especially the targets remain unclear, which was investigated in the present study. Briefly, the targets of IVT were predicted by bioinformatics and then were verified by multiple examinations using molecular docking, cellular thermal shift assay (CETSA), and Lipopolysaccharide/D-Galactosamine (LPS/D-GalN)-induced ALI animal model. The bioinformatic analysis predicted that the target genes of IVT against ALI were enriched into the PI3K/Akt and ERS-related pathways, in which, molecular docking and CETSA examination verified that the binding sites of IVT likely were PTEN, PI3K and BiP. Furthermore, the possible targets were also verified by animal experiments. The results revealed that IVT significantly ameliorated the hepatic injury, as evidenced by the attenuation of histopathological changes and the reduction in serum aminotransferase and total bilirubin activities. In addition, IVT treatment led to the reduction of PTEN, BiP and ERS-related targets expressions, as well as the elevation of PI3K, Akt and mTOR expressions. Notably, IVT significantly decreased total hepatic m6A level and m6A enrichment of PTEN and BiP, suggesting IVT regulated PTEN and BiP by modulating m6A modification. To sum up, the results indicate that IVT significantly ameliorates ALI, which is attributed to its ability to regulate the PI3K/Akt pathway and ERS by targeting PTEN, PI3K and BiP via modification of m6A. Our finding demonstrates that IVT may be a promising natural medicine for the treatment of ALI.

The Ginsenoside Rg1 Rescues Mitochondrial Disorders in Aristolochic Acid-Induced Nephropathic Mice.

Chronic exposure to aristolochic acid (AA) leads to renal interstitial fibrosis and nephropathy. In this study, we aimed to investigate the renoprotective effects of Panax ginseng extract (GE) and ginsenoside saponin (GS) on AA-induced nephropathy (AAN) in mice. Eighty female C3H/He mice were randomly divided into eight groups, including normal; AA (3 µg/mL for 56 days); AA with GE (125, 250, or 500 mg/kg/d for 14 days); and AA with important GE ingredients, Rg1, Rb1, or Rd (5 mg/kg/d for 14 days). Compared with the AA group, renal injuries were significantly decreased in the GE (250 mg/kg/d), Rb1, and Rg1 treatment groups. Rg1 exhibited the best renoprotection among all GS-treated groups. There were 24 peaks significantly altered among normal, AA, and AA + Rg1 groups, and four mitochondrial proteins were identified, including acyl-CoA synthetase medium-chain family member 2, upregulated during skeletal muscle growth 5 (Usmg5), mitochondrial aconitase 2 (ACO2), and cytochrome c oxidase subunit Va preprotein (COX5a). We demonstrated for the first time that the AAN mechanism and renoprotective effects of Rg1 are associated with expression of mitochondrial proteins, especially ACO2, Usmg5, and COX5a.

Evaluation of the nephrotoxicity and safety of low-dose aristolochic acid, extending to the use of Xixin (Asurum), by determination of methylglyoxal and d-lactate.

ETHNOPHARMACOLOGICAL RELEVANCE: Most Aristolochiaceae plants are prohibited due to aristolochic acid nephropathy (AAN), except Xixin (Asarum spp.). Xixin contains trace amounts of aristolochic acid (AA) and is widely used in Traditional Chinese Medicine. Methylglyoxal and d-lactate are regarded as biomarkers for nephrotoxicity. AIM OF THE STUDY: The use of Xixin (Asarum spp.) is essential and controversial. This study aimed to evaluate tubulointerstitial injury and interstitial renal fibrosis by determining urinary methylglyoxal and d-lactate after withdrawal of low-dose AA in a chronic mouse model. MATERIALS AND METHODS: C3H/He mice in the AA group (n = 24/group) were given ad libitum access to distilled water containing 3 µg/mL AA (0.5 mg/kg/day) for 56 days and drinking water from days 57 to 84. The severity of tubulointerstitial injury and fibrosis were evaluated using the tubulointerstitial histological score (TIHS) and Masson's trichrome staining. Urinary and serum methylglyoxal were determined by high-performance liquid chromatography (HPLC); urinary d-lactate were determined by column-switching HPLC. RESULTS: After AA withdrawal, serum methylglyoxal in the AA group increased from day 56 (429.4 ± 48.3 µg/L) to 84 (600.2 ± 99.9 µg/L), and peaked on day 70 (878.3 ± 171.8 µg/L; p < 0.05); TIHS and fibrosis exhibited similar patterns. Urinary methylglyoxal was high on day 56 (3.522 ± 1.061 µg), declined by day 70 (1.583 ± 0.437 µg) and increased by day 84 (2.390 ± 0.130 µg). Moreover, urinary d-lactate was elevated on day 56 (82.10 ± 18.80 µg) and higher from day 70 (201.10 ± 90.82 µg) to 84 (193.28 ± 61.32 µg). CONCLUSIONS: Methylglyoxal is induced after AA-induced tubulointerstitial injury, so methylglyoxal excretion and metabolism may be a detoxification and repair strategy. A low cumulative AA dose is the key factor that limits tubulointerstitial injury and helps to repair. Thus, AA-containing herbs, especially Xixin, should be used at low doses for short durations (less than one month).

Didymin ameliorates dexamethasone-induced non-alcoholic fatty liver disease by inhibiting TLR4/NF-κB and PI3K/Akt pathways in C57BL/6J mice.

The present study aimed to investigate the protective effects and mechanisms of Didymin from Mentha spicata on non-alcoholic fatty liver disease (NAFLD) induced by dexamethasone and high-fat diet (DEX/HFD) in C57BL/6J mice. Briefly, mice were acclimated for 5 days and then subjected to DEX/HFD from days 5 to 28; meanwhile, the animals were treated with Didymin or Silibinin from days 12 to 28. Key indicators of NAFLD were then detected, including the pathological changes of liver tissues, serum biochemical indicators, inflammation, oxidative stress, apoptosis and lipid metabolism. Besides, the expressions of pivotal genes and proteins of the TLR4/NF-κB and PI3K/Akt pathways were examined to further elucidate the mechanisms of Didymin. The results demonstrated that Didymin significantly extenuated hepatocyte damage and lipid disorder. Moreover, Didymin markedly decreased hepatocyte apoptosis by regulating the expressions of B-cell lymphoma-2 (Bcl-2) family and the expressions of the caspase family. Further study elucidated that Didymin decreased the expressions of toll-like receptor 4 (TLR4), as well as the phosphorylation of inhibitor of nuclear factor kappa-B (IκB) and nuclear factor kappa-B p65 (NF-κB p65), suggesting the inhibition of Didymin on the TLR4/NF-κB pathway. Similarly, the PI3K/Akt pathway was also inhibited by Didymin, as evidenced by the decrease in the phosphorylation levels of PI3K and Akt. In summary, this study indicates that Didymin mitigates NAFLD by alleviating lipidosis and suppressing the TLR4/NF-κB and PI3K/Akt pathways, which may be a potential natural medicine for the treatment of NAFLD.

Metabolic profiling of metformin treatment for low-level Pb-induced nephrotoxicity in rat urine.

Chronic kidney disease is a worldwide problem, and Pb contamination is a potential risk factor. Since current biomarkers are not sensitive for the diagnosis of Pb-induced nephrotoxicity, novel biomarkers are needed. Metformin has both hypoglycaemic effects and reno-protection ability. However, its mechanism of action is unknown. We aimed to discover the early biomarkers for the diagnosis of low-level Pb-induced nephrotoxicity and understand the mechanism of reno-protection of metformin. Male Wistar rats were randomly divided into control, Pb, Pb + ML, Pb + MH and MH groups. Pb (250 ppm) was given daily via drinking water. Metformin (50 or 100 mg/kg/d) was orally administered. Urine was analysed by nuclear magnetic resonance (NMR)-based metabolomics coupled with multivariate statistical analysis, and potential biomarkers were subsequently quantified. The results showed that Pb-induced nephrotoxicity was closely correlated with the elevation of 5-aminolevulinic acid, D-lactate and guanidinoacetic acid in urine. After co-treatment with metformin, 5-aminolevulinic acid and D-lactate were decreased. This is the first demonstration that urinary 5-aminolevulinic acid, D-lactate and guanidinoacetic acid could be early biomarkers of low-level Pb-induced nephrotoxicity in rats. The reno-protection of metformin might be attributable to the reduction of D-lactate excretion.

Arsenate removal from aqueous solution using chitosan-coated bentonite, chitosan-coated kaolinite and chitosan-coated sand: parametric, isotherm and thermodynamic studies.

In the present work, the removal efficiency of As(V) from aqueous solution using chitosan-coated bentonite (CCB), chitosan-coated kaolinite (CCK) and chitosan-coated sand (CCS) was evaluated. The chitosan-based adsorbents were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, the Brunauer-Emmett-Teller method and thermogravimetric analysis. Kinetic studies revealed that As(V) uptake using CCB, CCK and CCS fitted well with the pseudo-second order equation (R2 ≥ 0.9847; RMSE ≤ 9.1833). Equilibrium data show good correlation with the Langmuir model (R2 ≥ 0.9753; RMSE ≤ 8.5123; SSE ≤ 16.2651) for all adsorbents, which implies monolayer coverage onto homogenous energy sites. The Langmuir adsorption capacity for As(V) at pH 7.0 was determined to be 67.11, 64.85, and 16.78 mg/g for CCB, CCK and CCS, respectively. Thermodynamic studies show that As(V) uptake is exothermic in nature using CCK and endothermic using CCB and CCS. Moreover, adsorption of As(V) was feasible and spontaneous for CCB and CCS at 298 to 328 K. Results show that CCB is the most effective adsorbent in the removal of As(V) from water due to its high surface area and large pore diameter.

Proteomics analysis of altered proteins in kidney of mice with aristolochic acid nephropathy using the fluorogenic derivatization-liquid chromatography-tandem mass spectrometry method.

Aristolochic acid (AA) causes interstitial renal fibrosis, called aristolochic acid nephropathy (AAN). There is no specific indicator for diagnosing AAN, so this study aimed to investigate the biomarkers for AAN using a proteomics method. The C3H/He female mice were given ad libitum AA-distilled water (0.5 mg/kg/day) and distilled water for 56 days in the AA and normal groups, respectively. The AA-induced proteins in the kidney were investigated using a proteomics study, including fluorogenic derivatization with 7-chloro-N-[2-(dimethylamino)ethyl]-2,1,3-benzoxadiazole-4-sulfonamide, followed by high-performance liquid chromatography analysis and liquid chromatography tandem mass spectrometry with a MASCOT database searching system. There were two altered proteins, thrombospondin type 1 (TSP1) and G protein-coupled receptor 87 (GPR87), in the kidney of AA-group mice on day 56. GPR87, a tumorigenesis-related protein, is reported for the first time in the current study. The renal interstitial fibrosis was certainly induced in the AA-group mice under histological examination. Based on the results of histological examination and the proteomics study, this model might be applied to AAN studies in the future. TSP1 might be a novel biomarker for AAN, and the further role of GPR87 leading to AA-induced tumorigenesis should be researched in future studies.

In-silico ADME Studies for New Drug Discovery: From Chemical Compounds to Chinese Herbal Medicines.

Nowadays, in silico tools are widely used to provide the potential structure of the metabolites formed depending on the site of metabolism. These methods can also highlight the molecular moieties that help to direct the molecule into the cytochrome cavity so that the site of metabolism is in proximity to the catalytic center. In this minireview, we summarized three aspects of the in silico methods in the application of prediction of ADME (absorption, distribution, metabolism and excretion) properties of compounds: structure-based approaches for predicting molecular modeling of drug metabolizing enzymes; in silico metabolite prediction; and pharmacophore models for analysis substrate specificity. Moreover, we also extended the in silico studies in Chinese herbal medicines (CHM) research.

Accumulation of methylglyoxal and d-lactate in Pb-induced nephrotoxicity in rats.

Lead (Pb) is an environmental pollutant associated with several diseases, such as nephrotoxicity. Methylglyoxal (MG) is a reactive dicarbonyl compound formed during glycolysis and reported to increase in kidney damage. Metformin is used as an MG scavenger in the clinic. In this study, we investigated the mechanism of Pb-induced renal injury and the effect of metformin on Pb-induced nephrotoxicity. Eighteen Wistar rats were randomly divided into three groups: control, Pb, and Pb + metformin groups. Pb (250 ppm) was administered in drinking water, and 50 mg/kg of metformin was co-administered orally. After 28 days, the levels of MG and its metabolite d-lactate in urine, serum and renal tissues were examined. The elevation of renal MG (56.86 ± 17.47 vs 36.40 ± 5.69, p < 0.01) and urinary d-lactate (0.68 ± 0.28 vs 0.32 ± 0.13, p < 0.01) was observed in Pb-exposed rats compared with those in control rats. After co-treatment with metformin, these phenomena were attenuated. In the present study, it was demonstrated for the first time that urinary d-lactate might serve as the candidate marker for Pb-induced nephrotoxicity in the clinic, and metformin might be a new therapeutic candidate for Pb poisoning.

Structure of Mammalian Respiratory Supercomplex I1III2IV1.

The mammalian respiratory chain complexes assemble into supercomplexes (SCs) and reside in the inner mitochondrial membrane to transfer electrons and establish the proton gradient for complex V to synthesize ATP. The precise arrangement of SCs is largely unknown. Here, we report a 4.0-Å cryo-electron microscopy (cryo-EM) structure of the major SC in porcine heart, the 1.7-MDa SCI1III2IV1. The complex III (CIII) dimer and complex IV (CIV) bind at the same side of the L-shaped complex I (CI). Several accessory or supernumerary subunits of CI, such as NDUFA11, NDUFB4, NDUFB8, and NDUFB9, directly contribute to the oligomerization of CI, CIII, and CIV. COX7C and COX7A of CIV attach CIV to the concave surface formed by CIII and the distal end of membrane arm of CI. The structure suggests a possible mechanism by which electrons are transferred from NADH to cytochrome c and provides a platform for future functional dissection of respiration.

Identifying possible sites for antibody neutralization escape: Implications for unique functional properties of the C-terminal tail of Human Immunodeficiency Virus Type 1 gp41.

A previous amino acid sequence analyses from our laboratory reported nine potential sites in gp41 glycoprotein of HIV-1 that may contribute to virus escape from antibody neutralization. Besides four sites found outside the membrane of HIV-1 virus, five located in the C-terminal tail of gp41 specifically in the lentivirus lytic peptides motifs (LLPs). To further study the bioinformatical results, the virus infectivity assay and the standard neutralization assay were conducted on conservatively mutated virus. Two sites in the LLP3 domain stood out with the ability to alter the resistance of HIV-1 virus to certain broadly neutralizing antibodies (bNAbs). While the glycoprotein incorporation on the viral membrane and the interaction of the LLP3 domain with the lipid membrane remained unaltered, the increase in neutralization resistance of the mutant virus was associated with the changes on Env conformation. Our findings demonstrate different sensibility of bNAbs to mutations in the C-terminal tail and indicate an unrecognized potential role for even minor sequence variation in the C-terminal tail in modulating the antigenicity of the ectodomain of HIV-1 envelope glycoprotein complex.

A Novel 1,2-Dihydroquinoline Anticancer Agent and Its Delivery to Tumor Cells Using Cationic Liposomes.

AIM: We screened nine 1,2-dihydro-quinolines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay in HepG2 and SMMC cells and identified ethyl-2-cyano-2-(2- (methoxycarbonyl)allyl)quinoline-1(2H)-carboxylate (compound 5) as a potential anticancer agent. In order to further develop its anticancer therapeutic potential, we incorporated this agent into cationic liposomes for delivery to tumor cells. The characteristics of liposomes, their cytotoxicity and cellular uptake by tumor cells were investigated. We demonstrated that cationic 1,2-dioleoyl-3- trimethyl-ammonium-propane containing liposomes (cLips) loaded with compound 5 has superior antitumor activity compared to neutral liposomes. These data suggest cLip-compound 5 to be a promising agent that warrants further evaluation.

Cryopreservation of sweetpotato (Ipomoea batatas) and its pathogen eradication by cryotherapy.

Sweetpotato (Ipomoea batatas) ranks as the seventh most important staple crop in the world and the fifth in developing countries after rice, wheat, maize and cassava. Sweetpotato is mainly grown in developing countries, which account for more than 95% of total production of the whole world. Genetic resources, including cultivated varieties and wild species, are a prerequisite for novel sweetpotato breeding in both conventional and genetic engineering programs. Various cryopreservation protocols have been developed for shoot tips and embryogenic tissues. The former explants are preferred for long-term conservation of sweetpotato genetic resources, while the latter are valuable for sweetpotato genetic improvement. This review provides update comprehensive information on cryopreservation of sweetpotato shoot tips and embryogenic tissues. Plant pathogens such as viruses and phytoplasma severely hamper high yield and high quality production of sweetpotato. Thus, usage of pathogen-free planting materials is pivotal for sustainable sweetpotato production. Cryotherapy of shoot tips can efficiently eradicate sweetpotato pathogens such as viruses and phytoplasma. The mechanism behind pathogen eradication by cryotherapy of shoot tips has been elucidated. Pathogen eradication by cryotherapy provides an alternative, efficient strategy for production of pathogen-free plants. In addition, cryopreserved tissues may also be considered to be safer for exchange of germplasm between countries and regions.