[Research Progress on Characteristics of Human Microplastic Pollution and Health Risks].

Microplastic pollution is not only an environmental problem but also a social problem. Many studies have been conducted on the sources, abundance, and distribution of microplastics in the environment, but an understanding of human exposure levels and potential health risks remains very limited. Based on the bibliometric methods, the present review systematically summarized the exposure pathways of microplastics in humans, and then the characteristics and potential adverse impacts on human health were expounded upon. Available literature showed that microplastics in human bodies were mainly concentrated on sizes smaller than 50 µm, and polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) were the main polymers. Microplastics in environments entered human bodies mainly through food and respiratory pathways, then accumulated in lung and gastrointestinal tissues. Most importantly, small-sized microplastics could distribute in tissues and organs via the circulatory system. The results from lab-based toxicological experiments showed that microplastics not only posed threats to cell membrane integrity, immune stress, gut microbiota, and energy metabolism but also had potentially adverse impacts on the reproductive system. To further understand the health risks of microplastic pollution, it is necessary to promote research on the toxicological effects of microplastics as well as the inner mechanisms and also to establish risk assessment frameworks for evaluating microplastic pollution. These works are crucial to preventing the risks of microplastic pollution with scientific evidence.

Effect of environmental level of methomyl on hatching, morphology, immunity and development related genes expression in zebrafish (Danio rerio) embryo.

The extensive use of carbamate pesticides has led to a range of environmental and health problems, such as surface and groundwater contamination, and endocrine disorders in organisms. In this study, we focused on examining the effects of toxic exposure to the carbamate pesticide methomyl on the hatching, morphology, immunity and developmental gene expression levels in zebrafish embryos. Four concentrations of methomyl (0, 2, 20, and 200 µg/L) were administered to zebrafish embryos for a period of 96 h. The study found that exposure to methomyl accelerated the hatching process of zebrafish embryos, with the strongest effect recorded at the concentration of 2 µg/L. Methomyl exposure also trigged significantly reductions in heart rate and caused abnormalities in larvae morphology, and it also stimulated the synthesis and release of several inflammatory factors such as IL-1ß, IL-6, TNF-α and INF-α, lowered the IgM contents, ultimately enhancing inflammatory response and interfering with immune function. All of these showed the significant effects on exposure time, concentration and their interaction (Time × Concentration). Furthermore, the body length of zebrafish exposed to methomyl for 96 h was significantly shorter, particularly at higher concentrations (200 µg/L). Methomyl also affected the expression levels of genes associated with development (down-regulated igf1, bmp2b, vasa, dazl and piwi genes), demonstrating strong developmental toxicity and disruption of the endocrine system, with the most observed at the concentration of 200 µg/L and 96 h exposure to methomyl. The results of this study provide valuable reference information on the potential damage of methomyl concentrations in the environment on fish embryo development, while also supplementing present research on the immunotoxicity of methomyl.

Extract of Bletilla formosana callus elevates cellular antioxidative activity via Nrf2/HO-1 signaling pathway and inhibits melanogenesis in zebrafish.

BACKGROUND: Bletilla species are endangered terrestrial orchids used in natural skin care formulas in Asia for a long history. In order to explore the bioactivity potential of Bletilla species as a cosmetic ingredient in a sustainable resource manner, the callus of Bletilla formosana (Hayata) Schltr. was established and extracted by an eco-friendly supercritical fluid CO2 extraction (SFE-CO2) method. The intracellular reactive oxygen species (ROS) scavenging activity and antioxidation-related gene expression of the callus extract were evaluated in both Hs68 fibroblast cells and HaCaT keratinocytes. The melanogenesis-inhibitory effect was investigated in B16F10 melanoma cells and in an in vivo zebrafish model. RESULTS: The calli of B. formosana were propagated for 10-15 generations with a consistent yellow friable appearance and then subjected to SFE-CO2 extraction to obtain a yellow pasty extract. Obvious intracellular ROS scavenging activity of the extract was detected in both Hs68 and HaCaT cells with 64.30 ± 8.27% and 32.50 ± 4.05% reduction at the concentration of 250 µg/mL. Moreover, marked expression levels of heme oxygenase-1 (HO-1) and (NAD(P)H) quinone oxidoreductase-1 (NQO1) genes were detected after 6-h and 24-h treatments. These results indicate the cellular antioxidative activity of B. formosana callus extract was probably activated via the nuclear factor erythroid 2-related factor 2 (Nrf2)/HO-1 signaling pathway. Melanogenesis-inhibitory effect of the extract was observed in α-MSH stimuli-inducing B16F10 cells with 28.46% inhibition of intracellular melanin content at the concentration of 50 µg/ml. The effect was confirmed with in vivo zebrafish embryos that showed a relative pigmentation density of 80.27 ± 7.98% at the concentration of 100 µg/mL without toxicity. CONCLUSION: Our results shed light on a sustainable utilization of Bletilla species as a potential ingredient for skin.

Identification of competing endogenous RNA network in laryngeal squamous cell carcinoma.

OBJECTIVE: This study was conducted to investigate key long noncoding RNAs (lncRNAs) involved in competitive endogenous RNA (ceRNA) network associated with laryngeal squamous cell carcinoma (LSCC). MATERIALS AND METHODS: Three mRNA datasets, two miRNA datasets, and one lncRNA dataset of LSCC were downloaded from GEO database. Following the identification of differentially expressed mRNAs (DEmRNAs), (microRNAs) miRNAs (DEmiRNAs), and lncRNAs (DElncRNAs) in LSCC compared with adjacent tissues, functional enrichment of DEmRNAs was performed. Then, construction of the ceRNA (DElncRNA-DEmiRNA-DEmRNA) regulatory network and functional analyses of all DEmRNAs in ceRNA regulatory network were conducted. Quantitative real-time polymerase chain reactions (qRT-PCR) were used to detect the expression levels of selected DEmRNAs, DEmiRNAs, and DElncRNAs. RESULTS: A total of 3449 DEmRNAs, 40 DEmiRNAs, and 100 DElncRNAs were identified in LSCC. The ceRNA networks, which contained 132 DElncRNA-DEmiRNA pairs and 287 DEmiRNA-DEmRNA pairs, involving 44 lncRNAs, 3 miRNAs, and 271 mRNAs, were obtained. DEmRNAs in ceRNA regulatory networks were significantly enriched in pathways in cancer, prostate cancer, and aldosterone-regulated sodium reabsorption. Except for HCG22 and hsa-miR-1246, expressions of the others in the qRT-PCR results played the same pattern with that in our integrated analysis, generally. CONCLUSIONS: We concluded that HCG22/EGOT-hsa-miR-1275-FAM107A and HCG22/EGOT-hsa-miR-1246-Glycerol-3-phosphate dehydrogenase 1 like interaction pairs may play a central role in LSCC.

Effect of low­frequency repetitive transcranial magnetic stimulation on cognitive function in rats with medial temporal lobe epilepsy.

Epilepsy, especially the medial temporal lobe epilepsy (TLE), can result in cognitive impairment. Low­frequency repetitive magnetic stimulation (rTMS) has been verified to suppress neural excitability and reduce seizures. Given its potential in modifying cortical activity, we aimed to investigate its impact on cognitive function in the context of epilepsy, a condition where the use of rTMS has not been extensively explored. However, the influence on cognitive function has not yet been investigated. Therefore, this study aimed to investigate the effects of low­frequency rTMS on cognitive improvement in epileptic rats. Rats used in this study were randomly divided into five groups: the sham group, the epilepsy group, and three epilepsy groups treated with rTMS at different frequencies. Each group underwent the Morris water maze test to investigate hippocampus­dependent episodic memory, to evaluate their cognitive performance. Further assessments included patch clamp and western blot techniques to estimate the synaptic function in the hippocampus. Comparison between groups showed that low­frequency rTMS significantly reduced spontaneous recurrent seizures and improved spatial learning and memory impairment in epileptic rats. Additionally, rTMS remodeled the synaptic plasticity affected by seizures and notably enhanced the expression of AMPAR and synaptophysin. Low­frequency rTMS can antagonize the cognitive impairment caused by TLE, and promote synaptic connections.

Persistence of an epidemic cluster of Rhodotorula mucilaginosa in multiple geographic regions in China and the emergence of a 5-flucytosine resistant clone.

Rhodotorula mucilaginosa, an environmental yeast widely used in industry and agriculture, is also an opportunistic pathogen resistant to multi-antifungals. During the national surveillance in China, R. mucilaginosa has been documented from various hospitals and regions. At present, the molecular epidemiology of invasive infections caused by R. mucilaginosa and their resistance profiles to antifungals were unknown. Here we collected 49 strains from four hospitals located in different geographic regions from 2009 to 2019 in China, determined their genotypes using different molecular markers and quantified susceptibilities to various antifungals. Sequencing of ITS and D1/D2 regions in rDNA indicated that 73.5% (36/49) of clinical strains belong to same sequence type (rDNA type 2). Microsatellite (MT) genotyping with 15 (recently developed) tandem repeat loci identified 5 epidemic MT types, which accounted for 44.9% (22/49) of clinical strains, as well as 27 sporadic MT types. Microsatellite data indicated that the presence of an epidemic cluster including 35 strains (71.4%) repeatedly isolated in four hospitals for eight years. Single nucleotide variants (SNVs) from the whole genome sequence data also supported the clustering of these epidemic strains due to low pairwise distance. In addition, phylogenetic analysis of SNVs from these clinical strains, together with environmental and animal strains showed that the closely related epidemic cluster strains may be opportunistic, zoonotic pathogens. Also, molecular data indicated a possible clonal transmission of pan echinocandins-azoles-5-flucytosine resistant R. mucilaginosa strains in hospital H01. Our study demonstrated that R. mucilaginosa is a multi-drug resistant pathogen with the ability to cause nosocomial infection.

Cell-Penetrating Delivery of Nitric Oxide by Biocompatible Dinitrosyl Iron Complex and Its Dermato-Physiological Implications.

After the discovery of endogenous dinitrosyl iron complexes (DNICs) as a potential biological equivalent of nitric oxide (NO), bioinorganic engineering of [Fe(NO)2] unit has emerged to develop biomimetic DNICs [(NO)2Fe(L)2] as a chemical biology tool for controlled delivery of NO. For example, water-soluble DNIC [Fe2(µ-SCH2CH2OH)2(NO)4] (DNIC-1) was explored for oral delivery of NO to the brain and for the activation of hippocampal neurogenesis. However, the kinetics and mechanism for cellular uptake and intracellular release of NO, as well as the biocompatibility of synthetic DNICs, remain elusive. Prompted by the potential application of NO to dermato-physiological regulations, in this study, cellular uptake and intracellular delivery of DNIC [Fe2(µ-SCH2CH2COOH)2(NO)4] (DNIC-2) and its regulatory effect/biocompatibility toward epidermal cells were investigated. Upon the treatment of DNIC-2 to human fibroblast cells, cellular uptake of DNIC-2 followed by transformation into protein-bound DNICs occur to trigger the intracellular release of NO with a half-life of 1.8 ± 0.2 h. As opposed to the burst release of extracellular NO from diethylamine NONOate (DEANO), the cell-penetrating nature of DNIC-2 rationalizes its overwhelming efficacy for intracellular delivery of NO. Moreover, NO-delivery DNIC-2 can regulate cell proliferation, accelerate wound healing, and enhance the deposition of collagen in human fibroblast cells. Based on the in vitro and in vivo biocompatibility evaluation, biocompatible DNIC-2 holds the potential to be a novel active ingredient for skincare products.

Continual Decline in Azole Susceptibility Rates in Candida tropicalis Over a 9-Year Period in China.

BACKGROUND: There have been reports of increasing azole resistance in Candida tropicalis, especially in the Asia-Pacific region. Here we report on the epidemiology and antifungal susceptibility of C. tropicalis causing invasive candidiasis in China, from a 9-year surveillance study. METHODS: From August 2009 to July 2018, C. tropicalis isolates (n = 3702) were collected from 87 hospitals across China. Species identification was carried out by mass spectrometry or rDNA sequencing. Antifungal susceptibility was determined by Clinical and Laboratory Standards Institute disk diffusion (CHIF-NET10-14, n = 1510) or Sensititre YeastOne (CHIF-NET15-18, n = 2192) methods. RESULTS: Overall, 22.2% (823/3702) of the isolates were resistant to fluconazole, with 90.4% (744/823) being cross-resistant to voriconazole. In addition, 16.9 (370/2192) and 71.7% (1572/2192) of the isolates were of non-wild-type phenotype to itraconazole and posaconazole, respectively. Over the 9 years of surveillance, the fluconazole resistance rate continued to increase, rising from 5.7 (7/122) to 31.8% (236/741), while that for voriconazole was almost the same, rising from 5.7 (7/122) to 29.1% (216/741), with no significant statistical differences across the geographic regions. However, significant difference in fluconazole resistance rate was noted between isolates cultured from blood (27.2%, 489/1799) and those from non-blood (17.6%, 334/1903) specimens (P-value < 0.05), and amongst isolates collected from medical wards (28.1%, 312/1110) versus intensive care units (19.6%, 214/1092) and surgical wards (17.9%, 194/1086) (Bonferroni adjusted P-value < 0.05). Although echinocandin resistance remained low (0.8%, 18/2192) during the surveillance period, it was observed in most administrative regions, and one-third (6/18) of these isolates were simultaneously resistant to fluconazole. CONCLUSION: The continual decrease in the rate of azole susceptibility among C. tropicalis strains has become a nationwide challenge in China, and the emergence of multi-drug resistance could pose further threats. These phenomena call for effective efforts in future interventions.

Hepatocellular carcinoma progression in hepatitis B virus-related cirrhosis patients receiving nucleoside (acid) analogs therapy: A retrospective cross-sectional study.

BACKGROUND: Antiviral therapy cannot completely block the progression of hepatitis B to hepatocellular carcinoma (HCC). Furthermore, there are few predictors of early HCC progression and limited strategies to prevent progression in patients with HBV-related cirrhosis who receive nucleos(t)ide analog (NA) therapy. AIM: The study aim was to clarify risk factors and the diagnostic value of alpha-fetoprotein (AFP) for HCC progression in NA-treated hepatitis B virus (HBV)-related cirrhosis patients. METHODS: In this retrospective cross-sectional study, we analyzed the clinical data of 266 patients with HBV-related cirrhosis who received NA treatment between February 2014 and April 2020 at Zhejiang Provincial People's Hospital. The patients were divided into two groups, 145 who did not progress to HCC (No-HCC group), and 121 who progressed to HCC during NA treatment (HCC group). The logistic regression analysis was used to analyze the risk factors of HCC progression. The diagnostic value of AFP for HCC was evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: Univariate analysis showed that age ≥ 60 years (P = 0.001), hepatitis B and alcoholic etiology (P = 0.007), smoking history (P < 0.001), family history of HBV-related HCC (P = 0.002), lamivudine resistance (P = 0.011), HBV DNA negative (P = 0.023), aspartate aminotransferase > 80 U/L (P = 0.002), gamma-glutamyl transpeptidase > 120 U/L (P = 0.001), alkaline phosphatase > 250 U/L (P = 0.001), fasting blood glucose (FBG) ≥ 6.16 (mmol/L) (P = 0.001) and Child-Pugh class C (P = 0.005) were correlated with HCC progression. In multivariate analysis, age ≥ 60 years [hazard ratio (HR) = 3.089, 95% confidence interval (CI): 1.437-6.631, P = 0.004], smoking history (HR = 4.001, 95%CI: 1.836-8.716, P < 0.01), family history of HBV-related HCC (HR = 6.763, 95%CI: 1.253-36.499, P < 0.05), lamivudine resistance (HR = 2.949, 95%CI: 1.207-7.208, P = 0.018), HBV DNA negative (HR = 0.026, 95%CI: 0.007-0.139, P < 0.01), FBG ≥ 6.16 mmol/L (HR = 7.219, 95%CI: 3.716-14.024, P < 0.01) were independent risk factors of HCC progression. ROC of AFP for diagnosis of HCC was 0.746 (95%CI: 0.674-0.818). A cutoff value of AFP of 9.00 ug/L had a sensitivity of 0.609, and specificity of 0.818 for diagnosing HCC. CONCLUSION: Age ≥ 60 years, smoking history, family history of HCC, lamivudine resistance, HBV DNA negative, FBG ≥ 6.16 mmol/L were risk factors of HCC progression. Serum AFP had limited diagnostic value for HCC.

Identification and characterization of heat-responsive microRNAs at the booting stage in two rice varieties, 9311 and Nagina 22.

MicroRNAs (miRNAs) are small, non-coding, regulatory RNAs that play important roles in abiotic stress responses in plants, but their regulatory roles in the adaptive response to heat stress at the booting stage in two rice varieties, 9311 and Nagina 22, remain largely unknown. In this study, 464 known miRNAs and 123 potential novel miRNAs were identified. Of these miRNAs, a total of 90 differentially expressed miRNAs were obtained with 9311 libraries as the control group, of which 54 were upregulated and 36 were downregulated. To gain insight into functional significance, 2773 potential target genes of these 90 differentially expressed miRNAs were predicted. GO enrichment analysis showed that the predicted target genes of differentially expressed miRNAs included NACs, LACs, CSD, and Hsp40. KEGG pathway analysis showed that the target genes of these differentially expressed miRNAs were significantly enriched in the plant hormone signal transduction pathway. The expression levels of 10 differentially expressed miRNAs and their target genes obtained by qRT-PCR were largely consistent with the sequencing results. This study lays a foundation for the elucidation of the miRNA-mediated regulatory mechanisms in rice at elevated temperatures.

[Degradation Characteristics of Antibiotics During Composting of Four Types of Feces].

The widespread use of antibiotics in feed results in a large number of antibiotic residues in feces. Composting technology can degrade these residual antibiotics. A pilot-scale aerobic composting device was used to analyze the antibiotic residues and composting degradation characteristics of four types of feces (maggot manure, chicken manure, pig manure, and cow manure). Results showed that sulfonamides (SAs), fluoroquinolones (FQs), tetracycline (TCs), and macrolides (MAs) were the main antibiotics, and different type of feces had different dominant antibiotics. The contents of FQs and oxytetracycline (OTC) were none on the seventh day of the compost, and their degradation rates were the fastest. After composting, the degradation rate of doxycycline (DOX) in the four types of fecal composts was more than 85%. Meanwhile, the degradation rates of SAs in chicken, pig, and cow manure composts were also more than 80%, which was much lower in the one in maggot manure compost. MAs were only found in maggot manure, and the degradation rate was 70.79% after composting. Correlation analysis indicated that the water content and bulk density were the most important environmental factors affecting the degradation rates of antibiotics in the four types of fecal composts.

Studies of pathology and pharmacology of diabetic encephalopathy with KK-Ay mouse model.

AIMS: Pathogenesis of diabetic encephalopathy (DE) is not completely understood until now. The purposes of this study were to illustrate the changes in morphology, function, and important transporters in neurons and glia during DE, as well as to reveal the potential therapeutic effects of medicines and the diet control on DE. METHODS: Spontaneous obese KK-Ay mice were used to investigate diabetes-induced cognitive disorder, the morphology, function, and protein expression changes in impact animal and the cell level studies. The new drug candidate PHPB, donepezil, and low-fat food were used to observe the therapeutic effects. RESULTS: KK-Ay mice at 5 months of age showed typical characteristics of type 2 diabetes mellitus (T2DM） and appeared significant cognitive deficits. Morphological study showed microtubule-associated protein 2 (MAP2) expression was increased in hippocampal neurons and glial fibrillary acidic protein (GFAP) expression decreased in astrocytes. Meanwhile, the vesicular glutamate transporter 1 (vGLUT1) expression was increased and glucose transporter 1 (GLUT1) decreased, and the expression of brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF) was also reduced in KK-Ay mice. Microglia were activated, and IL-1ß and TNF-α were increased obviously in the brains of the KK-Ay mice. Most of the above changes in the KK-Ay mice at 5 months of age could be relieved by diet intervention (DR) or by treatment of donepezil or new drug candidate PHPB. CONCLUSION: KK-Ay mouse is a useful animal model for studying DE. The alterations of morphology, structure, and function of astrocyte and microglia in KK-Ay mice might be rescued by DR and by treatment of medicine. The proteins we reported in this study could be used as biomarkers and the potential drug targets for DE study and treatment.

Characteristic response of striatal astrocytes to dopamine depletion.

Astrocytes and astrocyte-related proteins play important roles in maintaining normal brain function, and also regulate pathological processes in brain diseases and injury. However, the role of astrocytes in the dopamine-depleted striatum remains unclear. A rat model of Parkinson's disease was therefore established by injecting 10 µL 6-hydroxydopamine (2.5 µg/µL) into the right medial forebrain bundle. Immunohistochemical staining was used to detect the immunoreactivity of glial fibrillary acidic protein (GFAP), calcium-binding protein B (S100B), and signal transducer and activator of transcription 3 (STAT3) in the striatum, and to investigate the co-expression of GFAP with S100B and STAT3. Western blot assay was used to measure the protein expression of GFAP, S100B, and STAT3 in the striatum. Results demonstrated that striatal GFAP-immunoreactive cells had an astrocytic appearance under normal conditions, but that dopamine depletion induced a reactive phenotype with obvious morphological changes. The normal striatum also contained S100B and STAT3 expression. S100B-immunoreactive cells were uniform in the striatum, with round bodies and sparse, thin processes. STAT3-immunoreactive cells presented round cell bodies with sparse processes, or were darkly stained with a large cell body. Dopamine deprivation induced by 6-hydroxydopamine significantly enhanced the immunohistochemical positive reaction of S100B and STAT3. Normal striatal astrocytes expressed both S100B and STAT3. Striatal dopamine deprivation increased the number of GFAP/S100B and GFAP/STAT3 double-labeled cells, and increased the protein levels of GFAP, S100B, and STAT3. The present results suggest that morphological changes in astrocytes and changes in expression levels of astrocyte-related proteins are involved in the pathological process of striatal dopamine depletion. The study was approved by Animal Care and Use Committee of Sun Yat-sen University, China (Zhongshan Medical Ethics 2014 No. 23) on September 22, 2014.

Genome maps across 26 human populations reveal population-specific patterns of structural variation.

Large structural variants (SVs) in the human genome are difficult to detect and study by conventional sequencing technologies. With long-range genome analysis platforms, such as optical mapping, one can identify large SVs (>2 kb) across the genome in one experiment. Analyzing optical genome maps of 154 individuals from the 26 populations sequenced in the 1000 Genomes Project, we find that phylogenetic population patterns of large SVs are similar to those of single nucleotide variations in 86% of the human genome, while ~2% of the genome has high structural complexity. We are able to characterize SVs in many intractable regions of the genome, including segmental duplications and subtelomeric, pericentromeric, and acrocentric areas. In addition, we discover ~60 Mb of non-redundant genome content missing in the reference genome sequence assembly. Our results highlight the need for a comprehensive set of alternate haplotypes from different populations to represent SV patterns in the genome.

Edaravone acts as a potential therapeutic drug against pentylenetetrazole-induced epilepsy in male albino rats by downregulating cyclooxygenase-II.

INTRODUCTION: The effects of edaravone against pentylenetetrazole (PTZ)-induced epilepsy in male albino rats were investigated. Edaravone is a well-known commercial drug used in the treatment of strokes and amyotrophic lateral sclerosis (ALS). Antioxidant and free radical scavenging activities of edaravone have been reported in patients with ALS. METHODS: In this study, the experimental groups were as follows: sham, control, 5 mg/kg edaravone, and 10 mg/kg edaravone. Behavioral assessment, determination of biochemical markers, apoptosis, nitric oxide (NO), and mRNA and protein expression of cyclooxygenase-II (COX-II) were carried out. Seizure incidence, including generalized tonic-clonic seizure (GTCS) and minimal clonic seizure (MCS), was directly associated with PTZ administration in rats. RESULTS: Edaravone supplementation substantially increased MCS and GTCS latency in rats, and biochemical markers were significantly altered in the brain tissue of PTZ-treated rats. Edaravone treatment normalized altered biochemical markers compared with the untreated control. Apoptosis and NO levels were significantly reduced by more than 50% compared to their respective controls. COX-II mRNA was increased by 130% in PTZ-treated rats, while edaravone supplementation reduced mRNA and protein expression of COX-II by more than 20% and 40%, respectively. Immunohistochemistry indicated that COX-II protein expression was reduced by 13.2% and 33.7% following supplementation with 5 and 10 mg/kg edaravone, respectively. CONCLUSION: Taken together, our results suggest that edaravone functions by downregulating the levels of COX-II and NO and is a potential candidate for the treatment of PTZ-induced epilepsy.

Gene Therapy and Photothermal Therapy of Layer-by-Layer Assembled AuNCs /PEI/miRNA/ HA Nanocomplexes.

BACKGROUND: MicroRNA (miRNA) therapy, which was widely considered to treat a series of cancer, has been confronted with numerous obstacles to being delivered into target cells because of its easy biodegradation and instability. METHODS: In this research, we successfully constructed 11-mercaptoundecanoic acid modified gold nanocages (AuNCs)/polyethyleneimine (PEI)/miRNA/hyaluronic acid (HA) complexes (abbreviated as AuNCs/PEI/miRNA/HA) using a layer-by-layer method for target-specific intracellular delivery of miRNA by HA receptor mediated endocytosis. RESULTS: The results of UV spectra, hydrodynamic diameter and zeta potential analyses confirmed the formation of AuNCs/PEI/ miRNA/HA complex with its average particle size of ca. 153 nm and surface charge of ca. -9.43 mV. Next, we evaluated the antitumor effect of the nanocomplex mediated by the combination of gene therapy and photothermal therapy (PTT) against hepatocellular carcinoma (HCC) in vitro. CONCLUSION: Our experimental results indicated that the AuNCs/PEI/miRNA/HA complex effectively delivered miRNA to the target cells and its antitumor effect was significantly enhanced by the combination of gene therapy and photothermal therapy. In addition, anti-miR-181b could promote Bel-7402 cell arrest in S phase and improve TIMP-3 mRNA expression. All these results suggested that AuNCs/PEI/miRNA/HA gene delivery system with combination of gene therapy and photothermal therapy might be exploited for HCC treatment.

Synthesis, structure, magnetism and photocatalysis of α-Fe2O3 nanosnowflakes.

In this work, a simple one-step hydrothermal method was developed to synthesize high-quality α-Fe2O3 nanoparticles with a snowflake-like microstructure. First, a series of binary supramolecular aggregates were prepared by a non-covalent combination between a polymer such as polyvinylpyrrolidone (PVP) and a complex such as potassium ferrocyanide (PF). Then, the aggregates were used as the precursors of the one-step hydrothermal reactions. The snowflake-like nanostructure has six-fold symmetry as a whole, and each petal is symmetric. This synthesis method has the characteristics of simplicity, rapidity, reliance, and high yield, and can be used for creating high-quality α-Fe2O3 nanoparticles. Moreover, our results show that the molar ratio of PVP to PF, reaction time and temperature play important roles in the generation of a complete snowflake structure from different angles. Also, the snowflake-like α-Fe2O3 nanostructure exhibits a much higher coercivity (2997 Oe) compared to those reported by others, suggesting a strong hysteresis behaviour, which promises potential applications in memory devices, and other fields. Further, the α-Fe2O3 nanosnowflakes show a much higher photocatalytic degradation activity for cationic organic dyes such as crystal violet, rhodamine 6G than for anionic dyes such as methyl orange. A possible photocatalytic mechanism was proposed for explaining the selectivity of the photocatalytic oxidation reaction of organic dyes. We believe that this study provides a direct link among coordination compounds of transition metals, their supramolecular aggregates with polymers, and controlled hydrothermal synthesis of high-quality inorganic metal oxide nanomaterials.

2-(4-methyl-thiazol-5-yl) ethyl nitrate maleate-potentiated GABAA receptor response in hippocampal neurons.

AIMS: 2-(4-methyl-thiazol-5-yl) ethyl nitrate maleate (NMZM), a derivative of clomethiazole (CMZ), had been investigated for the treatment of Alzheimer's disease (AD). The beneficial effects of NMZM in AD included reversing cognitive deficit, improving learning and memory as well as neuroprotection. The pharmacological effects of NMZM on GABAA receptors were reported previously; however, the mechanisms were unclear and were explored therefore. RESULTS: In this study, we demonstrated that NMZM improved learning and memory by alleviating scopolamine-induced long-term potentiation (LTP) suppression in the dentate gyrus of rats, indicating that NMZM had protective effects against scopolamine-induced depression of LTP. Next, we investigated the action of NMZM on GABAA receptors in hippocampal neurons and the binding site of NMZM on GABAA receptors. NMZM directly activated GABAA receptors in hippocampal neurons in a weak manner. However, NMZM could potentiate the response of GABAA receptors to GABA and NMZM positively modulated GABAA receptors with an EC50 value of 465 µmol/L at 3 µmol/L GABA while this potentiation at low concentration of GABA (1, 3 µmol/L) was more significant than that at high concentration (10, 30 µmol/L). In addition, NMZM could enhance GABA currents after using diazepam and pentobarbital, the positive modulators of GABAA receptors. NMZM could not affect the etomidate-potentiated GABAA current. It suggested that the binding site of NMZM on GABAA receptors is the same as etomidate. CONCLUSIONS: These results provided support for the neuroprotective effect of NMZM, which was partly dependent on the potentiation of GABAA receptors. The etomidate binding site might be a new target for neuronal protection and for drug development.

Involvement of Met and Kr-h1 in JH-Mediated Reproduction of Female Bactrocera dorsalis (Hendel).

Juvenile hormone (JH) prevents metamorphosis during insect larval stages and promotes adult reproductive processes. Krüppel-homolog 1 (Kr-h1), a zinc finger transcription factor assumed to be induced by JH via the JH receptor methoprene-tolerant (Met), mediates the antimetamorphic effect of JH in insects, but its function in JH-mediated reproductive processes has not been fully explored. In this study, Met and Kr-h1 involved in the JH signaling pathway were first cloned and identified from the oriental fruit fly, Bactrocera dorsalis, an important pest infesting fruit and vegetables worldwide. Subsequent spatiotemporal expression analysis revealed that Met and Kr-h1 were both highly expressed in 7-day-old adults and fat body of female adults, respectively. Treatment with a JH analog (methoprene) significantly induced the expression of JH signaling and vitellogenin (Vg) genes and accelerated ovary development. RNA interference (RNAi) further revealed that either Met or Kr-h1 depletion at the adult stage of B. dorsalis impeded ovary development, with significantly lower egg production noted as well. In addition, rescue through methoprene application after RNAi stimulated the expression of JH signaling and Vg genes. Although there were still differences in ovary phenotype between rescued insects and the pre-RNAi control, ovary redevelopment with a larger surface area was observed, consistent with the spatiotemporal expression and phenotypes recorded in the original methoprene experiment. Our data reveal the involvement of Met and Kr-h1 in insect vitellogenesis and egg production, thus indicating the crucial role of the JH signaling pathway in insect reproduction.

Function of the natalisin receptor in mating of the oriental fruit fly, Bactrocera dorsalis (Hendel) and testing of peptidomimetics.

Natalisins (NTLs) are conservative neuropeptides, which are only found in arthropods and are documented to regulate reproductive behaviors in insects. In our previous study, we have confirmed that NTLs regulate the reproductive process in an important agricultural pest, Bactrocera dorsalis (Hendel). Hence, in this study, to further confirm the in vivo function of NTL receptor (NTLR) and assess the potential of NTLR as an insecticide target, RNA interference targeting NTLR mRNA was performed. We found that mating frequencies of both males and females were reduced by RNAi-mediated knockdown of the NTLR transcript, while there was no effect on mating duration. Moreover, we functionally expressed the B. dorsalis NTLR in Chinese Hamster Ovary (CHO) cells and was co-transfected with an aequorin reporter to measure ligand activities. A total of 13 biostable multi-Aib analogs were tested for agonistic and antagonistic activities. While most of these NTL analogs did not show strong activity, one analog (NLFQV[Aib]DPFF[Aib]TRamide) had moderate antagonistic activity. Taken together, we provided evidence for the important roles of NTLR in regulating mating frequencies of both male and female in this fly and also provided in vitro data on mimetic analogs that serve as leading structures for the development of agonists and antagonists to disrupt the NTL signaling pathway.