Advances in Nanozymes as a Paradigm for Viral Diagnostics and Therapy.

Over the past few decades, humankind has constantly encountered new viral species that create havoc in the socioeconomic balance worldwide. Among the method to combat these novel viral infections, fast and point-of-care diagnosis is of prime importance to contain the spreading of viral infections. However, most sensitive diagnostic systems for viral infections are time-consuming and require well-trained professionals, making it difficult for the patients. In recent years nanozymes emerged as promising therapeutic and fast diagnostic tools due to their multienzyme-like catalytic performance. Nanozymes can be designed using inorganic or organic components with tailorable physicochemical surface properties, enabling the attachment of various molecules and species on the surface of the nanozyme for specific recognition. In addition to the composition, the multienzyme-like catalytic performance can be modulated by the shape and size of the nanoparticles. Due to their multicatalytic abilities, nanozymes can be used for fast diagnosis and therapy for viral infections. Here we attempt to focus on the insights and recent explorations on the advances in designing various types of nanozymes as a theranostic tool for viral infections. Thus, this review intends to generate interest in the clinical translation of nanozymes as a theranostic tool for viral infections by providing knowledge about the multidisciplinary potential of nanozyme. SIGNIFICANCE STATEMENT: The multienzyme-like properties of nanozymes suggest their role in diagnosing and treating various diseases. Although the potential roles of nanozymes for various viral infections have been studied in the last few decades, no review provides recent explorations on designing various types of nanozymes for the detection and treatment of viral infections. This review provides insights into designing nanozymes to diagnose and treat viral infections, assisting future researchers in developing clinically translatable nanozymes to combat novel viral infections.

Accelerated full-thickness skin wound tissue regeneration by self-crosslinked chitosan hydrogel films reinforced by oxidized CNC-AgNPs stabilized Pickering emulsion for quercetin delivery.

BACKGROUND: The non-toxic self-crosslinked hydrogel films designed from biocompatible materials allow for controlled drug release and have gathered remarkable attention from healthcare professionals as wound dressing materials. Thus, in the current study the chitosan (CS) film is infused with oil-in-water Pickering emulsion (PE) loaded with bioactive compound quercetin (Qu) and stabilized by dialdehyde cellulose nanocrystal-silver nanoparticles (DCNC-AgNPs). The DCNC-AgNPs play a dual role in stabilizing PE and are involved in the self-crosslinking with CS films. Also, this film could combine the advantage of the controlled release and synergistic wound-healing effect of Qu and AgNPs. RESULTS: The DCNC-AgNPs were synthesized using sodium periodate oxidation of CNC. The DCNC-AgNPs were used to stabilize oil-in-water PE loaded with Qu in its oil phase by high speed homogenization. Stable PEs were prepared by 20% v/v oil: water ratio with maximum encapsulation of Qu in the oil phase. The Qu-loaded PE was then added to CS solution (50% v/v) to prepare self-crosslinked films (CS-PE-Qu). After grafting CS films with PE, the surface and cross-sectional SEM images show an inter-penetrated network within the matrix between DCNC and CS due to the formation of a Schiff base bond between the reactive aldehyde groups of DCNC-AgNPs and amino groups of CS. Further, the addition of glycerol influenced the extensibility, swelling ratio, and drug release of the films. The fabricated CS-PE-Qu films were analyzed for their wound healing and tissue regeneration potential using cell scratch assay and full-thickness excisional skin wound model in mice. The as-fabricated CS-PE-Qu films showed great biocompatibility, increased HaCat cell migration, and promoted collagen synthesis in HDFa cells. In addition, the CS-PE-Qu films exhibited non-hemolysis and improved wound closure rate in mice compared to CS, CS-Qu, and CS-blank PE. The H&E staining of the wounded skin tissue indicated the wounded tissue regeneration in CS-PE-Qu films treated mice. CONCLUSION: Results obtained here confirm the wound healing benefits of CS-PE-Qu films and project them as promising biocompatible material and well suited for full-thickness wound healing in clinical applications.

Protective effect of zinc oxide nanoparticles synthesized using Cassia alata for DSS-induced ulcerative colitis in mice model.

The most prevalent form of inflammatory bowel disease (IBD), ulcerative colitis (UC), is characterized by persistent inflammation of the colorectal mucosa. It is asymptomatic, whereas Crohn's disease (CD) causes patchy lesions in the gastrointestinal tract. Men and women suffer equally from ulcerative colitis, which usually strikes in the second and third decades of life and becomes more common in senior citizens. In the present study, we produced zinc oxide nanoparticles using the natural herbal plant, Cassia alata. Zinc oxide nanoparticles have remarkable antimicrobial and antitumor benefits in the field of biomedical science. Furthermore, the synthesized zinc oxide nanoparticles (ZnO NPs) were characterized using UV, XRD, FTIR, and SEM analyses. The XRD analysis confirmed the crystallite nature and purity of the synthesized nanoparticles. Zinc oxide nanoparticles with a uniform size and partially agglomerated morphology were verified by SEM analysis. We investigated the protective effects of environmentally friendly zinc oxide nanoparticles in dextran sodium sulfate-induced ulcerative colitis mouse models. Green synthesized Cassia alata zinc oxide nanoparticles (CA ZnO NPs) reversed weight loss, disease activity index, colon shortening, and colon histological damage. Zinc oxide nanoparticles reduce hypersensitivity, oxidative stress, and inflammation, and protect the mucosal layer. Green synthesized CA ZnO NPs demonstrated protection against dextran sodium sulfate-induced ulcerative colitis via anti-inflammatory activity.

The Cannabinoids, CBDA and THCA, Rescue Memory Deficits and Reduce Amyloid-Beta and Tau Pathology in an Alzheimer's Disease-like Mouse Model.

Most studies related to hemp are focused on Cannabidiol (CBD) and Tetrahydrocannabinol (THC); however, up to 120 types of phytocannabinoids are present in hemp. Hemp leaves contain large amounts of Cannabidiolic acid (CBDA) and Tetrahydrocannabinolic acid (THCA), which are acidic variants of CBD and THC and account for the largest proportion of CBDA. In recent studies, CBDA exhibited anti-hyperalgesia and anti-inflammatory effects. THCA also showed anti-inflammatory and neuroprotective effects that may be beneficial for treating neurodegenerative diseases. CBDA and THCA can penetrate the blood-brain barrier (BBB) and affect the central nervous system. The purpose of this study was to determine whether CBDA and THCA ameliorate Alzheimer's disease (AD)-like features in vitro and in vivo. The effect of CBDA and THCA was evaluated in the Aß1-42-treated mouse model. We observed that Aß1-42-treated mice had more hippocampal Aß and p-tau levels, pathological markers of AD, and loss of cognitive function compared with PBS-treated mice. However, CBDA- and THCA-treated mice showed decreased hippocampal Aß and p-tau and superior cognitive function compared with Aß1-42-treated mice. In addition, CBDA and THCA lowered Aß and p-tau levels, alleviated calcium dyshomeostasis, and exhibited neuroprotective effects in primary neurons. Our results suggest that CBDA and THCA have anti-AD effects and mitigate memory loss and resilience to increased hippocampal Ca2+, Aß, and p-tau levels. Together, CBDA and THCA may be useful therapeutic agents for treating AD.

Assessment of bacteriophage-encoded endolysin as a potent antimicrobial agent against antibiotic-resistant Salmonella Typhimurium.

This study was designed to evaluate the potential of using newly purified Salmonella phage-encoded endolysin LysPB32 as novel antibiotic alternative. The endolysin LysPB32 was characterized by analyzing pH and thermal stability, lytic spectrum, antimicrobial activity, and mutant frequency against Salmonella Typhimurium KCCM 40253 (STKCCM), S. Typhimurium ATCC 19585 (STATCC), S. Typhimurium CCARM 8009 (STCCARM), Klebsiella pneumoniae ATCC 23357 (KPATCC), K. pneumoniae CCARM 10237 (KPCCARM), Pseudomonas aeruginosa ATCC 27853 (PAATCC), Listeria monocytogenes ATCC 1911 (LMATCC), Staphylococcus aureus ATCC 25923 (SAATCC), and S. aureus CCARM 3080 (SACCARM). The molecular weight of LysPB32 is 17 kDa that was classified as N-acetyl-ß-d-muramidase. The optimum activity of LysPB32 against the outer membrane (OM) permeabilized STKCCM, STATCC, and STCCARM was observed at 37 °C and pH 6.5. LysPB32 had a broad spectrum of muralytic activity against antibiotic-sensitive STKCCM (41 mOD/min), STATCC (32 mOD/min), and SBKACC (25 mOD/min) and antibiotic-resistant STCCARM (35 mOD/min) and KPCCARM (31 mOD/min). The minimum inhibitory concentrations (MICs) of polymyxin B against STKCCM, STCCARM, and STATCC were decreased by 4-, 4-, and 8-folds, respectively, when treated with LysPB32. The combination of LysPB32 and polymyxin B effectively inhibited the growth of STKCCM, STCCARM, and STATCC after 24 h of incubation at 37 °C, showing 4.9-, 4.4-, and 3.3-log reductions, respectively. The mutant frequency was low in STKCCM, STCCARM, and STATCC treated with combination of LysPB32-polymyxin B system. The results suggest the LysPB32-polymyxin system can be a potential candidate for alternative therapeutic agent to control antibiotic-resistant pathogens.

Next-generation engineered nanogold for multimodal cancer therapy and imaging: a clinical perspectives.

Cancer is one of the significant threats to human life. Although various latest technologies are currently available to treat cancer, it still accounts for millions of death each year worldwide. Thus, creating a need for more developed and novel technologies to combat this deadly condition. Nanoparticles-based cancer therapeutics have offered a promising approach to treat cancer effectively while minimizing adverse events. Among various nanoparticles, nanogold (AuNPs) are biocompatible and have proved their efficiency in treating cancer because they can reach tumors via enhanced permeability and retention effect. The size and shape of the AuNPs are responsible for their diverse therapeutic behavior. Thus, to modulate their therapeutic values, the AuNPs can be synthesized in various shapes, such as spheres, cages, flowers, shells, prisms, rods, clusters, etc. Also, attaching AuNPs with single or multiple targeting agents can facilitate the active targeting of AuNPs to the tumor tissue. The AuNPs have been much explored for photothermal therapy (PTT) to treat cancer. In addition to PTT, AuNPs-based nanoplatforms have been investigated for combinational multimodal therapies in the last few years, including photodynamic therapy, chemotherapy, radiotherapy, immunotherapy, etc., to ablate cancer cells. Thus, the present review focuses on the recent advancements in the functionalization of AuNPs-based nanoconstructs for cancer imaging and therapy using combinatorial multimodal approaches to treat various cancers.

Extract from Black Soybean Cultivar A63 Extract Ameliorates Atopic Dermatitis-like Skin Inflammation in an Oxazolone-Induced Murine Model.

Black soybean has been used in traditional medicine to treat inflammatory diseases, cancer, and diabetes and as a nutritional source since ancient times. We found that Korean black soybean cultivar A63 has more cyanidin-3-O-glucoside, (C3G), procyanidin B2 (PB2), and epicatechin (EPC) contents than other cultivars and has beneficial effects on cell viability and anti-oxidation. Given the higher concentration of anthocyanidins and their strong anti-oxidant activity, we predicted that A63 extract could relieve inflammatory disease symptoms, including those of atopic dermatitis (AD). Here, we evaluated the anti-AD activity of A63 extract in an oxazolone (OXA)-induced mouse model. A63 extract treatment significantly reduced epidermal thickness and inflammatory cell infiltration, downregulated the expression of AD gene markers, including Interleukin (IL)-4 and IL-5, and restored damaged skin barrier tissues. Furthermore, A63 extract influenced the activation of the signal transducer and activator of transcription (STAT) 3 and STAT6, extracellular regulatory kinase (ERK), and c-Jun N-terminal kinase (JNK) signaling pathways, which play a crucial role in the development of AD. Altogether, our results suggest that A63 can ameliorate AD-like skin inflammation by inhibiting inflammatory cytokine production and STAT3/6 and Mitogen-activated protein kinase (MAPK) signaling and restoring skin barrier function.

Ulmusakidian, a new coumarin glycoside and antifungal phenolic compounds from the root bark of Ulmus davidiana var. japonica.

Bioactivity-driven LC/MS-based phytochemical analysis of the root bark extract of Ulmus davidiana var. japonica led to the isolation of 10 compounds including a new coumarin glycoside derivative, ulmusakidian (1). The structure of the new compound was elucidated using extensive spectroscopic analyses via 1D and 2D NMR spectroscopic data interpretations, HR-ESIMS, and chemical transformation. The isolated compounds 1-10 were tested for their antifungal activity against human fungal pathogens Cryptococcus neoformans and Candida albicans. Compounds 9 and 10 showed antifungal activity against C. neoformans, with the lowest minimal inhibitory concentration (MIC) of 12.5-25.0 µg/mL, whereas none of the compounds showed antifungal activity against C. albicans.

Ginkgonitroside, a new nitrophenyl glycoside and bioactive compounds from Ginkgo biloba leaves controlling adipocyte and osteoblast differentiation.

Eight compounds (1-8) including one novel nitrophenyl glycoside, ginkgonitroside (1) were isolated from the leaves of Ginkgo biloba, a popular medicinal plant. The structure of the new compound was characterized using extensive spectroscopic analyses via 1D and 2D NMR data interpretations, HR-ESIMS, and chemical transformation. To the best of our knowledge, the present study is the first to report the presence of nitrophenyl glycosides, which are relatively unique phytochemicals in natural products, in G. biloba. The isolated compounds (1-8) were examined for their effects on the regulation of mesenchymal stem cell (MSC) differentiation. Compounds 1-3 and 8 were able to suppress MSC differentiation toward adipocytes. In contrast, compounds 5 and 8 showed activity promoting osteogenic differentiation of MSCs. These findings demonstrate that the active compounds showed regulatory activity on MSC differentiation between adipocytes and osteocytes.

Polyquaternium enhances the colloidal stability of chitosan-capped platinum nanoparticles and their antibacterial activity.

Here, for the first time, we have developed a novel green synthesis method where chitosan acts as a reducing agent and as a colloidal stabilizer, together with polyquaternium for the synthesis of platinum nanoparticles (PtNPs). It was observed that only chitosan-stabilized PtNPs (Ch@PtNPs) were stable up to pH 5, with a diameter of around 89 nm. The diameter of the Ch@PtNPs increased with the increase in pH, indicating the instability of Ch@PtNPs at neutral and alkaline mediums. However, when polyquaternium (PQ) (a cationic polymer) was added as a stabilizer along with chitosan, the diameter of chitosan/polyquaternium stabilized PtNPs (Ch/PQ@PtNPs), i.e. 87 nm, remained almost constant up to pH 9. Similarly, the pH-dependent decrease in the surface charge of Ch@PtNPs was also attenuated with the addition of polyquaternium. This indicates high colloidal stability of Ch/PQ@PtNPs in acidic, neutral, as well as alkaline mediums. It was observed that Ch/PQ@PtNPs exhibited high antibacterial activity againstStaphylococcus aureus, as compared to uncapped PtNPs and Ch@PtNPs. Thus, the addition of PQ increases the antibacterial properties of Ch/PQ@PtNPs againstStaphylococcus aureusby enhancing the stability of PtNPs at neutral pH.

Central composite design for the development of carvedilol-loaded transdermal ethosomal hydrogel for extended and enhanced anti-hypertensive effect.

BACKGROUND: Carvedilol, the anti-hypertensive drug, has poor bioavailability when administered orally. Ethosomes-mediated transdermal delivery is considered a potential route of administration to increase the bioavailability of carvedilol. The central composite design could be used as a tool to optimize ethosomal formulation. Thus, this study aims to optimize carvedilol-loaded ethosomes using central composite design, followed by incorporation of synthesized ethosomes into hydrogels for transdermal delivery of carvedilol. RESULTS: The optimized carvedilol-loaded ethosomes were spherical in shape. The optimized ethosomes had mean particle size of 130 ± 1.72 nm, entrapment efficiency of 99.12 ± 2.96%, cumulative drug release of 97.89 ± 3.7%, zeta potential of - 31 ± 1.8 mV, and polydispersity index of 0.230 ± 0.03. The in-vitro drug release showed sustained release of carvedilol from ethosomes and ethosomal hydrogel. Compared to free carvedilol-loaded hydrogel, the ethosomal gel showed increased penetration of carvedilol through the skin. Moreover, ethosomal hydrogels showed a gradual reduction in blood pressure for 24 h in rats. CONCLUSIONS: Taken together, central composite design can be used for successful optimization of carvedilol-loaded ethosomes formulation, which can serve as the promising transdermal delivery system for carvedilol. Moreover the carvedilol-loaded ethosomal gel can extend the anti-hypertensive effect of carvedilol for a longer time, as compared to free carvedilol, suggesting its therapeutic potential in future clinics.

Identification of Tyrosinase Inhibitors and Their Structure-Activity Relationships via Evolutionary Chemical Binding Similarity and Structure-Based Methods.

Tyrosinase is an enzyme that plays a crucial role in the melanogenesis of humans and the browning of food products. Thus, tyrosinase inhibitors that are useful to the cosmetic and food industries are required. In this study, we have used evolutionary chemical binding similarity (ECBS) to screen a virtual chemical database for human tyrosinase, which resulted in seven potential tyrosinase inhibitors confirmed through the tyrosinase inhibition assay. The tyrosinase inhibition percentage for three of the new actives was over 90% compared to 61.9% of kojic acid. From the structural analysis through pharmacophore modeling and molecular docking with the human tyrosinase model, the pi-pi interaction of tyrosinase inhibitors with conserved His367 and the polar interactions with Asn364, Glu345, and Glu203 were found to be essential for tyrosinase-ligand interactions. The pharmacophore features and the docking models showed high consistency, revealing the possible essential binding interactions of inhibitors to human tyrosinase. We have also presented the activity cliff analysis that successfully revealed the chemical features related to substantial activity changes found in the new tyrosinase inhibitors. The newly identified inhibitors and their structure-activity relationships presented here will help to identify or design new human tyrosinase inhibitors.

Influence of Material Properties on the Damage-Reporting and Self-Healing Performance of a Mechanically Active Dynamic Network Polymer in Coating Applications.

We conducted a detailed investigation of the influence of the material properties of dynamic polymer network coatings on their self-healing and damage-reporting performance. A series of reversible polyacrylate urethane networks containing the damage-reporting diarylbibenzofuranone unit were synthesized, and their material properties (e.g., indentation modulus, hardness modulus, and glass-transition temperature) were measured conducting nanoindentation and differential scanning calorimetry experiments. The damage-reporting and self-healing performances of the dynamic polymer network coatings exhibited opposite tendencies with respect to the material properties of the polymer network coatings. Soft polymer network coatings with low glass-transition temperature (~10 °C) and indentation hardness (20 MPa) exhibited better self-healing performance (almost 100%) but two times worse damage-reporting properties than hard polymer network coatings with high glass-transition temperature (35~50 °C) and indentation hardness (150~200 MPa). These features of the dynamic polymer network coatings are unique; they are not observed in elastomers, films, and hydrogels, whereby the polymer networks are bound to the substrate surface. Evidence indicates that controlling the polymer's physical properties is a key factor in designing high-performance self-healing and damage-reporting polymer coatings based on mechanophores.

Postharvest Drying Techniques Regulate Secondary Metabolites and Anti-Neuroinflammatory Activities of Ganoderma lucidum.

Ganoderma lucidum extract is a potent traditional remedy for curing various ailments. Drying is the most important postharvest step during the processing of Ganoderma lucidum. The drying process mainly involves heat (36 h at 60 °C) and freeze-drying (36 h at -80 °C). We investigated the effects of different postharvest drying protocols on the metabolites profiling of Ganoderma lucidum using GC-MS, followed by an investigation of the anti-neuroinflammatory potential in LPS-treated BV2 microglial cells. A total of 109 primary metabolites were detected from heat and freeze-dried samples. Primary metabolite profiling showed higher levels of amino acids (17.4%) and monosaccharides (8.8%) in the heat-dried extracts, whereas high levels of organic acids (64.1%) were present in the freeze-dried samples. The enzymatic activity, such as ATP-citrate synthase, pyruvate kinase, glyceraldehyde-3-phosphatase dehydrogenase, glutamine synthase, fructose-bisphosphate aldolase, and D-3-phosphoglycerate dehydrogenase, related to the reverse tricarboxylic acid cycle were significantly high in the heat-dried samples. We also observed a decreased phosphorylation level of the MAP kinase (Erk1/2, p38, and JNK) and NF-κB subunit p65 in the heat-dried samples of the BV2 microglia cells. The current study suggests that heat drying improves the production of ganoderic acids by the upregulation of TCA-related pathways, which, in turn, gives a significant reduction in the inflammatory response of LPS-induced BV2 cells. This may be attributed to the inhibition of NF-κB and MAP kinase signaling pathways in cells treated with heat-dried extracts.

RIG-I RNA helicase activation of IRF3 transcription factor is negatively regulated by caspase-8-mediated cleavage of the RIP1 protein.

Excessive responses to pattern-recognition receptors are prevented by regulatory mechanisms that affect the amounts and activities of the downstream signaling proteins. We report that activation of the transcription factor IRF3 by the ribonucleic acid sensor RIG-I was restricted by caspase-8-mediated cleavage of the RIP1 protein, which resulted in conversion of RIP1 from a signaling enhancer to a signaling inhibitor. The proteins RIP1 and caspase-8 were recruited to the RIG-I complex after viral infection and served antagonistic regulatory roles. Conjugation of ubiquitin chains to RIP1 facilitated assembly of the RIG-I complex, resulting in enhanced phosphorylation of IRF3. However, the ubiquitination of RIP1 also rendered it susceptible to caspase-8-mediated cleavage that yielded an inhibitory RIP1 fragment. The dependence of RIP1 cleavage on the same molecular change as that facilitating RIG-I signaling allows for RIG-I signaling to be restricted in its duration without compromising its initial activation.

Calvatianone, a Sterol Possessing a 6/5/6/5-Fused Ring System with a Contracted Tetrahydrofuran B-Ring, from the Fruiting Bodies of Calvatia nipponica.

Calvatia nipponica is an extremely rare mushroom with a limited number of studies on its chemical components and biological activities published. Here we report the isolation of a novel sterol, calvatianone (1), possessing a 6/5/6/5-fused ring system with a contracted tetrahydrofuran B-ring, and four known steroids (2-5) from the fruiting bodies of C. nipponica. The structure of calvatianone including its absolute configuration was determined by NMR spectroscopic analyses, HR-ESIMS, gauge-including atomic orbital NMR chemical shift calculations, and ECD calculations. Ergosterol peroxide (3) and cyathisterol (4) suppressed the cell viability increase induced by 17ß-estradiol in MCF-7 breast cancer cell lines, suggesting a possible approach for these compounds to serve as ERα antagonists.

Identification of Anti-Inflammatory Compounds from Hawaiian Noni (Morinda citrifolia L.) Fruit Juice.

Noni (Morinda citrifolia L.) fruit juice has been used in Polynesia as a traditional folk medicine and is very popular worldwide as a functional food supplement. In this study, compounds present in Hawaiian Noni fruit juice, with anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells were identified. Five compounds were isolated using a bioassay-driven technique and phytochemical analysis of noni fruit juice: asperulosidic acid (1), rutin (2), nonioside A (3), (2E,4E,7Z)-deca-2,4,7-trienoate-2-O-ß-d-glucopyranosyl-ß-d-glucopyranoside (4), and tricetin (5). The structures of these five compounds were determined via NMR spectroscopy and LC/MS. In an anti-inflammatory assay, compounds 1-5 inhibited the production of nitric oxide (NO), which is a proinflammatory mediator, in LPS-stimulated macrophages. Moreover, the mechanisms underlying the anti-inflammatory effects of compounds 1-5 were investigated. Parallel to the inhibition of NO production, treatment with compounds 1-5 downregulated the expression of IKKα/ß, I-κBα, and NF-κB p65 in LPS-stimulated macrophages. Furthermore, treatment with compounds 1-5 downregulated the expression of nitric oxide synthase and cyclooxygenase-2. Thus, these data demonstrated that compounds 1-5 present in noni fruit juice, exhibited potential anti-inflammatory activity; these active compounds may contribute preventively and therapeutically against inflammatory diseases.

SIRT2 reduces actin polymerization and cell migration through deacetylation and degradation of HSP90.

SIRT2, a member of the class III histone deacetylase family, has been identified as a tumor suppressor, which is associated with various cellular processes including metabolism and proliferation. However, the effects of SIRT2 on cancer cell migration caused by cytoskeletal rearrangement remain uncertain. Here we show that SIRT2 inhibits cell motility by suppressing actin polymerization. SIRT2 regulates actin dynamics through HSP90 destabilization and subsequent repression of LIM kinase (LIMK) 1/cofilin pathway. SIRT2 directly interacts with HSP90 and regulates its acetylation and ubiquitination. In addition, the deacetylase activity of SIRT2 is required for the regulation of actin polymerization and the ubiquitin-mediated proteasomal degradation of HSP90 induced by SIRT2.

Assessment of antibiotic resistance in bacteriophage-insensitive Klebsiella pneumoniae.

This study was design to evaluate the physiological properties of bacteriophage-insensitive Klebsiella pneumoniae (BIKP) mutants in association with the antibiotic cross-resistance, ß-lactamase activity, and gene expression. Klebsiella pneumoniae ATCC 23357(KPWT), ciprofloxacin-induced antibiotic-resistant K. pneumoniae ATCC 23357 (KPCIP), and clinically isolated antibiotic-resistant K. pneumoniae 10263 (KPCLI) were used to isolate BIKP mutants against KPB1, PBKP02, PBKP21, PBKP29, PBKP33, and PBKP35. PBKP35-induced mutants, including bacteriophage-insensitive K. pneumoniae ATCC 23357 (BIKPWT), ciprofloxacin-induced K. pneumoniae ATCC 23357 (BIKPCIP), and clinically isolated antibiotic-resistant K. pneumoniae CCARM 10263 (BIKPCLI). BIKPWT, BIKPCIP, and BIKPCLI were resistant to Klebsiella bacteriophages, KPB1, PBKP02, PBKP21, PBKP29, and PBKP33. The antibiotic cross-resistance to cefotaxime, cephalothin, chloramphenicol, ciprofloxacin, erythromycin, kanamycin, levofloxacin, and nalidixic acid was observed in BIKPWT. The relative expression levels of vagC was increased by more than 8-folds in BIKPWT, corresponding to the increased ß-lactamase activity. The aac(6')-Ib-cr was overexpressed in BIKP mutants, responsible for aminoglycoside and quinolone resistance. The phage-resistant mutants decreased the antibiotic susceptibilities in association with ß-lactamase activity and antibiotic resistance-related gene expression. The results pointed out the cross-resistance of BIKP mutants to antibiotics, which might be considered when applying for the therapeutic use of bacteriophage.

Proteomics-based discrimination of differentially expressed proteins in antibiotic-sensitive and antibiotic-resistant Salmonella Typhimurium, Klebsiella pneumoniae, and Staphylococcus aureus.

This study was designed to compare the differentially expressed proteins between antibiotic-sensitive and antibiotic-resistant Salmonella Typhimurium, Klebsiella pneumonia, and Staphylococcus aureus. The susceptibilities of wild-type (WT), ciprofloxacin (CIP) and/or oxacillin (OXA)-induced, and clinically isolated resistant (CCARM) S. Typhimurium (STWT, STCIP, and STCCARM), K. pneumoniae (KPWT, KPCIP, and KPCCARM), and S. aureus (SAWT, SACIP, SAOXA, and SACCARM) to antibiotics were determined using broth microdilution assay. STCIP was highly resistant to piperacillin (MIC > 512 µg/ml), KPCIP was resistant to chloramphenicol (128 µg/ml) and norfloxacin (16 µg/ml), SACIP was resistant to fluoroquinolones (32 µg/ml), and SAOXA was resistant to ceftriaxone (32 µg/ml). The protein profiles of antibiotic-sensitive and antibiotic-resistant strains were determined using 2-DE analysis followed by LC-MS/MS. The commonly expressed proteins of STWT-STCIP, STWT-STCCARM, KPWT-KPCIP, KPWT-KPCCARM, SAWT-SACIP, SAWT-SAOXA, and SAWT-SACCARM were 763, 677, 677, 469, 261, 259, and 226, respectively. The unique protein spots were observed 57 (6.5%), 80 (11.5%), and 68 (13.9%), respectively, for STCCARM, KPCCARM, and SACCARM. The highly up-regulated protein, PrsA (10-fold), was observed in STCIP resistant to ciprofloxacin (128-fold), levofloxacin (32-fold), norfloxacin (64-fold), and piperacillin (> 16-fold). The up-regulated proteins (YadC, FimA, and RplB) in KPCIP resistant to chloramphenicol (> 32-fold), ciprofloxacin (32-fold), levofloxacin (6-fold), norfloxacin (128-fold), and sparfloxacin (64-fold). AcrB and RpoB were up-regulated in SACCARM resistant to multiple antibiotics. The differentially expressed proteins were related to the antibiotic resistance of STWT, STCIP, STCCARM, KPWT, KPCIP, KPCCARM, SAWT, SACIP, SAOXA, and SACCARM. The resistance-associated proteins could be useful biomarkers for detecting antibiotic-resistant pathogens.