Ready for renascence in mosquito: The regulation of gene expression in Plasmodium sexual development.

Malaria remains one of the most perilous vector-borne infectious diseases for humans globally. Sexual gametocyte represents the exclusive stage at which malaria parasites are transmitted from the vertebrate to the Anopheles host. The feasible and effective approach to prevent malaria transmission is by addressing the sexual developmental processes, that is, gametocytogenesis and gametogenesis. Thus, this review will comprehensively cover advances in the regulation of gene expression surrounding the transmissible stages, including epigenetic, transcriptional, and post-transcriptional control.

Plasmodium transcription repressor AP2-O3 regulates sex-specific identity of gene expression in female gametocytes.

Male and female gametocytes are sexual precursor cells essential for mosquito transmission of malaria parasite. Differentiation of gametocytes into fertile gametes (known as gametogenesis) relies on the gender-specific transcription program. How the parasites establish distinct repertoires of transcription in the male and female gametocytes remains largely unknown. Here, we report that an Apetala2 family transcription factor AP2-O3 operates as a transcription repressor in the female gametocytes. AP2-O3 is specifically expressed in the female gametocytes. AP2-O3-deficient parasites produce apparently normal female gametocytes. Nevertheless, these gametocytes fail to differentiate into fully fertile female gametes, leading to developmental arrest in fertilization and early development post-fertilization. AP2-O3 disruption causes massive upregulation of transcriptionally dormant male genes and simultaneously downregulation of highly transcribed female genes in the female gametocytes. AP2-O3 targets a substantial proportion of the male genes by recognizing an 8-base DNA motif. In addition, the maternal AP2-O3 is removed after fertilization, which is required for the zygote to ookinete development. Therefore, the global transcriptional repression of the male genes in the female gametocytes is required for safeguarding female-specific transcriptome and essential for the mosquito transmission of Plasmodium.

Scalable and low-cost fabrication of hydrophobic PVDF/WS2 porous membrane for highly efficient solar steam generation.

Solar steam generation based on the light-to-heat conversion via photothermal materials has been considered as one of emerged technologies for utilizing solar energy to produce clean water. Here, a hydrophobic PVDF/WS2 porous membrane for highly efficient solar steam generation was prepared by a scalable and low-cost method. The WS2 photothermal materials were fabricated through a simple ball milling, and then a non-solvent induced phase inversion method was used to fabricate the porous PVDF/WS2 membrane. The PVDF/WS2 evaporator could absorb the sunlight of 90.58% from UV to NIR region due to the multiscattering of the porous structure and the synergistic effect of WS2 and seawater. Moreover, the PVDF/WS2 evaporator exhibits the hydrophobic properties. Taking the advantages mentioned above, our evaporator could manifest the evaporation rate of 4.15 kgm-2h-1 with the solar thermal efficiency of 94.2% under 3 sun irradiation, as well as an outstanding durability upon continuous running. Also, the evaporator shows both the excellent seawater desalination and sewage treatment ability. Outdoor experiments illustrate that the evaporator has practical applications under a natural sunlight condition. The numerous advantages of our PVDF/WS2 evaporator, including the high solar-thermal efficiency, the outstanding durability, and the simple and scalable manufacture process, may provide a potential photothermal material for the commercial solar desalination application and wastewater treatment.

Construction of hierarchical 2D/2D Ti3C2/MoS2 nanocomposites for high-efficiency solar steam generation.

Solar steam generation has been considered one of the most promising approaches for dealing with the energy and freshwater resource crises in recent years. However, achieving high efficiency in photo-thermal conversion remains a considerable challenge. Here, a series of hierarchical Ti3C2/MoS2 nanocomposites were designed for steam generation by a hydrothermal method. When the mass fraction of MoS2 reached 65 wt% (TM-3), the Ti3C2/MoS2 nanocomposite presented a strong broad-band light absorption of 92.4% from the UV to NIR region because of the accordion-like layered structure. The evaporation rate and solar-thermal conversion efficiency of the TM-3 with as-fabricated evaporator could reach 1.36 kg·m-2·h-1 and 87.2% under 1 kW/m2, due to the excellent light absorption ability of TM-3 and the low thermal energy loss (8.8%) of the evaporator. Meanwhile, TM-3 permits the evaporator to have remarkable cycle stability because of its hydrophobic properties. Moreover, TM-3 showed excellent seawater desalination and wastewater treatment abilities. Thus, the excellent light absorption ability, photo-thermal conversion efficiency, and stability of the overall system suggested that these nanocomposites show great potential applications in synergetic solar desalination and sewage treatment.

NK cell-derived exosomes improved lung injury in mouse model of Pseudomonas aeruginosa lung infection.

BACKGROUND: Pseudomonas aeruginosa (PA) is one of the most common bacteria that causes lung infection in hospital. The aim of our study is to explore the role and action mechanism of NK cells in lung PA infection. METHODS: In this present study, 2.5 × 108 CFU/mouse PA was injected into murine trachea to make lung PA infection mouse model. Anti-asialo GM1 was used to inhibit NK cell. The percentage of NK cells was ensured by flow cytometry, and the M1- and M2-polarized macrophages were determined by flow cytometry, qRT-PCR, and ELISA assay. Besides, H&E staining was performed to ensure the pathological changes in lung tissues. Transmission electron microscopy and western blot were carried out to identify the exosome. RESULTS: Here, in the mouse model of PA lung infection, NK cell depletion caused M2 polarization of lung macrophage, and exacerbated PA-induced lung injury. Next, our data shown that M2 macrophage polarization was enhanced when the generation of NK cell-derived exosome was blocked in the co-culture system of NK cells and macrophages. Subsequently, we demonstrated that NK cells promoted M1 macrophage polarization both in PA-infected macrophage and the mouse model of PA lung infection, and attenuated lung injury through exosome. CONCLUSION: Overall, our data proved that NK cell may improve PA-induced lung injury through promoting M1 lung macrophage polarization by secreting exosome. Our results provide a new idea for the treatment of PA lung infection.

An intracellular membrane protein GEP1 regulates xanthurenic acid induced gametogenesis of malaria parasites.

Gametocytes differentiation to gametes (gametogenesis) within mosquitos is essential for malaria parasite transmission. Both reduction in temperature and mosquito-derived XA or elevated pH are required for triggering cGMP/PKG dependent gametogenesis. However, the parasite molecule for sensing or transducing these environmental signals to initiate gametogenesis remains unknown. Here we perform a CRISPR/Cas9-based functional screening of 59 membrane proteins expressed in the gametocytes of Plasmodium yoelii and identify that GEP1 is required for XA-stimulated gametogenesis. GEP1 disruption abolishes XA-stimulated cGMP synthesis and the subsequent signaling and cellular events, such as Ca2+ mobilization, gamete formation, and gametes egress out of erythrocytes. GEP1 interacts with GCα, a cGMP synthesizing enzyme in gametocytes. Both GEP1 and GCα are expressed in cytoplasmic puncta of both male and female gametocytes. Depletion of GCα impairs XA-stimulated gametogenesis, mimicking the defect of GEP1 disruption. The identification of GEP1 being essential for gametogenesis provides a potential new target for intervention of parasite transmission.

Suppression of miR-147b contributed to H37Rv-infected macrophage viability and migration in tuberculosis in vitro.

BACKGROUND: Tuberculosis (TB) is a severe infectious disease. It was reported that microRNAs played important roles in tuberculosis. However, the role of miR-147b in the disease remained unveiling. METHODS: Tuberculosis cell model was established using macrophage THP-1 cells infected with H37Rv strain. RT-qPCR was first for examination of miR-147b relative expression. Cell viabilities were then measured with MTT. Cell transfection was to interfere the relative expression of miR-147b or C11orf87 in infected cells. RT-qPCR was adopted to confirm the transfection efficiency. Luciferase assay verified the binding sites between miR-147b and C11orf87. Migration was examined by scratch and relative protein expression of EMT biomarkers and phosphorylation of Pi3K and AKT were assessed via Western blot. RESULT: MiR-147b expression was higher and cell viability decreased in H32Rv-THP-1 cells. Cell viability was shown higher after miR-147b downregulation. Luciferase assay confirmed the binding. RT-qPCR found C11orf87 expression was lower in the H32Rv-THP-1 cells. MTT suggested that cell viability fell with the decrease of C11orf87 in infectious cells. Moreover, when H32Rv-THP-1 cells were co-transfected with miR-147b inhibitor and si-C11orf87, cell viability, migration and EMT and activation of Pi3K/AKT pathway was partially reversed compared with mere downregulation of miR-147b. CONCLUSION: miR-147b might regulate macrophage proliferation and migration through targeting C11orf87 via Pi3K/AKT pathway in Tuberculosis in vitro, which calls for in-depth inter-cellular researches and animal researches to further support that miR-147b/C11orf87 axis might be a potential therapeutic target for the molecular treatment of Tuberculosis in the future.

Construction of noble-metal-free TiO2 nanobelt/ZnIn2S4 nanosheet heterojunction nanocomposite for highly efficient photocatalytic hydrogen evolution.

A binary nanocomposite composed of two-dimensional (2D) ultrathin ZnIn2S4 nanosheets and one-dimension (1D) TiO2 nanobelts was prepared and applied as a noble-metal-free photocatalyst for hydrogen evolution under solar-light irradiation. The TiO2 nanobelt/ZnIn2S4 nanosheet heterojunction nanocomposites show higher light absorption capacity, larger surface area and higher separation of charge carriers in comparison to pristine TiO2 and ZnIn2S4. As a result, the hydrogen production over the TiO2/ZnIn2S4 nanocomposite with 15 wt% TiO2 can reach up to 348.21 µmol · g-1 · h-1, even without noble metals, which is about 26 and 2.3 times higher than the pristine TiO2 and ZnIn2S4, respectively. Meanwhile, a possible photocatalytic mechanism of TiO2/ZnIn2S4 heterojunction nanocomposites was proposed and corroborated by photoluminescence (PL) spectroscopy and photoelectrochemical (PEC) results. This work paves a way for developing low-cost and high-efficiency noble-metal-free photocatalytic systems for solar-to-hydrogen evolution.

Generation of Plasmodium yoelii malaria parasite carrying double fluorescence reporters in gametocytes.

Male and female gametocytes are the infectious forms critical for malaria transmission and targets of intervention. Gametocytes are generally produced in relatively small numbers, and it has been difficult to obtain pure male and female gametocytes for various studies. Male and female gametocytes expressing unique fluorescence reporters have been generated for both Plasmodium falciparum and Plasmodium berghei parasites, which allows isolation of large numbers of pure male and female gametocytes and has greatly contributed to our understanding of gametocyte biology. To establish Plasmodium yoelii as another model for studying gametocytogenesis, here we generate a parasite line with male and female gametocytes expressing GFP or mCherry reporter, respectively, using CRISPR/Cas9-mediated gene editing method. We first inserted genes encoding intact fluorescence proteins downstream of parasite coding region of ccp2 and Dhc1 genes, respectively, generating the knockin parasites producing ccp2::mCherry (female) and Dhc1::gfp (male) gametocytes. We next obtained a parasite clone carrying double-fluorescent reporters by genetically crossing the ccp2::mCherry and Dhc1::gfp lines. The resulting double-labeled DFsc7 parasite displays normal development during the whole life cycle and expresses the fluorescence proteins in male and female gametocyte separately. This parasite strain provides a new platform for facilitating studies of gametocyte biology and malaria transmission.

A Cas9 transgenic Plasmodium yoelii parasite for efficient gene editing.

The RNA-guided endonuclease Cas9 has applied as an efficient gene-editing method in malaria parasite Plasmodium. However, the size (4.2 kb) of the commonly used Cas9 from Streptococcus pyogenes (SpCas9) limits its utility for genome editing in the parasites only introduced with cas9 plasmid. To establish the endogenous and constitutive expression of Cas9 protein in the rodent malaria parasite P. yoelii, we replaced the coding region of an endogenous gene sera1 with the intact SpCas9 coding sequence using the CRISPR/Cas9-mediated genome editing method, generating the cas9-knockin parasite (PyCas9ki) of the rodent malaria parasite P. yoelii. The resulted PyCas9ki parasite displays normal progression during the whole life cycle and possesses the Cas9 protein expression in asexual blood stage. By introducing the plasmid (pYCs) containing only sgRNA and homologous template elements, we successfully achieved both deletion and tagging modifications for different endogenous genes in the genome of PyCas9ki parasite. This cas9-knockin PyCas9ki parasite provides a new platform facilitating gene functions study in the rodent malaria parasite P. yoelii.

Systematic CRISPR-Cas9-Mediated Modifications of Plasmodium yoelii ApiAP2 Genes Reveal Functional Insights into Parasite Development.

Malaria parasites have a complex life cycle with multiple developmental stages in mosquito and vertebrate hosts, and different developmental stages express unique sets of genes. Unexpectedly, many transcription factors (TFs) commonly found in eukaryotic organisms are absent in malaria parasites; instead, a family of genes encoding proteins similar to the plant Apetala2 (ApiAP2) transcription factors is expanded in the parasites. Several malaria ApiAP2 genes have been shown to play a critical role in parasite development; however, the functions of the majority of the ApiAP2 genes remain to be elucidated. In particular, no study on the Plasmodium yoelii ApiAP2 (PyApiAP2) gene family has been reported so far. This study systematically investigated the functional roles of PyApiAP2 genes in parasite development. Twenty-four of the 26 PyApiAP2 genes were selected for disruption, and 12 were successfully knocked out using the clustered regularly interspaced short palindromic repeat-CRISPR-associated protein 9 (CRISPR-Cas9) method. The effects of gene knockout (KO) on parasite development in mouse and mosquito stages were evaluated. Ten of 12 successfully disrupted genes, including two genes that have not been functionally characterized in any Plasmodium species previously, were shown to be critical for P. yoelii development of sexual and mosquito stages. Additionally, seven of the genes were labeled for protein expression analysis, revealing important information supporting their functions. This study represents the first systematic functional characterization of the P. yoelii ApiAP2 gene family and discovers important insights on the roles of the ApiAP2 genes in parasite development.IMPORTANCE Malaria is a parasitic disease that infects hundreds of millions of people, leading to an estimated 0.35 million deaths in 2015. A better understanding of the mechanism of gene expression regulation during parasite development may provide important clues for disease control and prevention. In this study, systematic gene disruption experiments were performed to study the functional roles of members of the Plasmodium yoelii ApiAP2 (PyApiAP2) gene family in parasite development. Genes that are critical for the development of male and female gametocytes, oocysts, and sporozoites were characterized. The protein expression profiles for seven of the PyApiAP2 gene products were also analyzed, revealing important information on their functions. This study provides expression and functional information for many PyApiAP2 genes, which can be explored for disease management.

CRISPR/Cas9 mediated sequential editing of genes critical for ookinete motility in Plasmodium yoelii.

CRISPR/Cas9 has been successfully adapted for gene editing in malaria parasites including Plasmodium falciparum and Plasmodium yoelii. However, the reported methods were limited to editing one gene at a time. In practice, it is often desired to modify multiple genetic loci in a parasite genome. Here we describe a CRISPR/Cas9 mediated genome editing method that allows successive modification of more than one gene in the genome of P. yoelii using an improved single-vector system (pYCm) we developed previously. Drug resistant genes encoding human dihydrofolate reductase (hDHFR) and a yeast bifunctional protein (yFCU), with cytosine deaminase (CD) and uridyl phosphoribosyl transferase (UPRT) activities in the plasmid, allowed sequential positive (pyrimethamine, Pyr) and negative (5-fluorocytosine, 5FC) selections and generation of transgenic parasites free of the episomal plasmid after genetic modification. Using this system, we were able to efficiently tag a gene of interest (Pyp28) and subsequently disrupted two genes (Pyctrp and Pycdpk3) that are individually critical for ookinete motility. Disruption of the genes either eliminated (Pyctrp) or greatly reduced (Pycdpk3) ookinete forward motility in matrigel in vitro and completely blocked oocyst development in mosquito midgut. The method will greatly facilitate studies of parasite gene function, development, and disease pathogenesis.

Efficient editing of malaria parasite genome using the CRISPR/Cas9 system.

Malaria parasites are unicellular organisms residing inside the red blood cells, and current methods for editing the parasite genes have been inefficient. The CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats and Cas9 endonuclease-mediated genome editing) system is a new powerful technique for genome editing and has been widely employed to study gene function in various organisms. However, whether this technique can be applied to modify the genomes of malaria parasites has not been determined. In this paper, we demonstrated that Cas9 is able to introduce site-specific DNA double-strand breaks in the Plasmodium yoelii genome that can be repaired through homologous recombination. By supplying engineered homologous repair templates, we generated targeted deletion, reporter knock-in, and nucleotide replacement in multiple parasite genes, achieving up to 100% efficiency in gene deletion and 22 to 45% efficiencies in knock-in and allelic replacement. Our results establish methodologies for introducing desired modifications in the P. yoelii genome with high efficiency and accuracy, which will greatly improve our ability to study gene function of malaria parasites. Importance: Malaria, caused by infection of Plasmodium parasites, remains a world-wide public health burden. Although the genomes of many malaria parasites have been sequenced, we still do not know the functions of approximately half of the genes in the genomes. Studying gene function has become the focus of many studies; however, editing genes in malaria parasite genomes is still inefficient. Here we designed several efficient approaches, based on the CRISPR/Cas9 system, to introduce site-specific DNA double-strand breaks in the Plasmodium yoelii genome that can be repaired through homologous recombination. Using this system, we achieved high efficiencies in gene deletion, reporter tagging, and allelic replacement in multiple parasite genes. This technique for editing the malaria parasite genome will greatly facilitate our ability to elucidate gene function.

Invasion inhibition by a MEK inhibitor correlates with the actin-based cytoskeleton in lung cancer A549 cells.

Metastasis remains the primary cause of lung cancer. The molecules involved in metastasis may be candidates for new targets in the therapy of lung cancer. The MEK/ERK signaling pathway has been highlighted in a number of studies on invasiveness and metastasis. In this paper, we show that the MEK inhibitor U0126 induces flattened morphology, remodels the actin-based cytoskeleton, and potently inhibits chemotaxis and Matrigel invasion in the human lung cancer A549 cell line. Furthermore, downregulation of ERK by small interfering RNA significantly inhibits the invasion of A549 cells and induces stress fiber formation. Taken together, our findings provide the first evidence that the inhibition of invasion of lung cancer A549 cells by inhibiting MEK/ERK signaling activity is associated with remodeling of the actin cytoskeleton, suggesting a novel link between MEK/ERK signaling-mediated cell invasion and the actin-based cytoskeleton.

[Effects of topographic factors on the distribution patterns of ground plants with different growth forms in montane forests in North Guangdong, China].

By using canonical correspondence analysis (CCA), this paper studied the effects of small-scale topographic changes on the distribution patterns of ground plants with different growth forms in the montane evergreen broad-leaved forest in Chebaling National Nature Reserve of North Guangdong, China. It was observed that slope aspect, slope grade, and slope position had significantly integrative effects on the distribution patterns of four growth form ground plants (fern, liana, herb, and shrub). Slope aspect had significant effects on the distribution patterns of all four ground plants but slope position didn't have, whereas slope grade only affected the distribution pattern of shrub significantly. From shady slope to semi-shady slope, and to semi-sunny slope, the abundance of the four growth form ground plants decreased gradually, indicating that shade plants were dominant in the ground vegetation of subtropical montane evergreen broad-leaved forest. Most shrubs were shade-tolerant species, and their change patterns of richness and diversity with slope aspect were the same as the change pattern of abundance. Shrubs were sensitive to the change of slope grade, and richer on gentle slopes. In hilly and low mountains, slope position changed little, and had less effects on the distribution patterns of ground plants. At stand-level, horizontal topographic factor (slope grade aspect) had much greater effects on the distribution patterns of ground plants, as compared with vertical topographic factors (slope grade and slope position), which suggested that slope aspect was the major factor affecting the water and heat conditions in subtropical montane forest.

[Metabolic remodeling and the alteration of related receptors expressions in failing heart].

OBJECTIVE: To explore the metabolic remodeling and its correlative mechanisms in human failing heart by contrasting the content of substrate, the activity of correlative enzyme and the mRNA and protein expression of beta(3)-adrenoceptor and peroxisome proliferator-activate receptor alpha (PPARalpha). METHODS: Cardo ac tossie samples were talem from 20 patients with heart failure of valvular heart disease and undergoing valvuloplasty operation as well as 6 subjects being killed in accidents (as control). The levels of free fat acid (FFA) and the activity of succinate dehydrogenase (SDH), Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase of the myocardial tissue were measured. Protein and mRNA expression of beta(3)-adrenergic receptor and peroxisome proliferator-activated receptor alpha (PPARalpha) in myocardial tissue were analyzed using reverse transcriptase-polymerase chain reaction and Western-blot respectively. RESULTS: In the failing hearts, the contents of FA and expression of beta 3 adrenoceptor mRNA and protein were obviously higher than those in the control group, the activity of SDH, Na(+)-K(+)-ATPase, Ca(2+)-Mg(2+)-ATPase and expression of PPARalpha mRNA and protein were on the contrary. CONCLUSION: The human failing myocardium is characterized by metabolic remodeling and it maybe concerned with the upregulation of beta3 adrenoceptor and downregulation of PPARalpha.

[Expressions of beta(3)-adrenoceptor and peroxisome proliferator-activated receptor alpha in human failing heart].

OBJECTIVE: To explore the changes on the content of substrate, the activity of correlative enzyme and the mRNA and protein expressions of beta(3)-adrenoceptor and peroxisome proliferator-activated receptor alpha (PPARalpha) in human failing heart. METHOD: Papillary muscles from 20 patients with heart failure during mitral valves replacement and 6 control subjects died of non-cardiac accidents were obtained and free fat acid (FFA), lactic acid (LD) and the activity of Na(+)K(+)-ATPase and Ca(2+)Mg(2+)-ATPase, protein and mRNA expressions of beta(3)-adrenergic receptor and PPARalpha were measured. RESULT: In the failing heart, the contents of fat acid, LD and expression of beta(3)-adrenoceptor mRNA and protein were significantly higher while the activity of Na(+)K(+)-ATPase and Ca(2+)Mg(2+)-ATPase, expressions of PPARalpha at mRNA and protein levels were significantly lower than those in control myocardium. CONCLUSION: Metabolic remodeling (upregulation of beta(3)-adrenoceptor and downregulation of PPARalpha) might contribute to the pathophysiology of heart failure.

[The relationship between expressions of beta1-, beta2-, beta3-adrenoceptor mRNA of myocardium and cardiac function in patients with heart failure].

OBJECTIVE: To investigate the alteration of expressions of beta(1)-, beta(2)-, beta(3)-adrenoceptor mRNA in human myocardial tissue and the relation between their expressions and cardiac function in patient with heart failure. METHODS: The mRNA expressions of beta(1)-, beta(2)- and beta(3)-adrenergic receptors in myocardial tissue were analyzed by using the reverse transcriptase-polymerase chain reaction in 24 patients with heart failure of valvular heart disease and 5 control subjects. RESULTS: Beta(1)-adrenergic receptor mRNA expressions in myocardium were significantly lower in patients with heart failure than those in control subjects, and progressively reduced with aggravation of heart function. By contrast, beta(3)-adrenoceptor mRNA expressions were significantly higher in patients with heart failure than those in controls, and progressively elevated with aggravation of cardiac function. No difference was observed in beta(2)-adrenergic receptor among all groups. CONCLUSION: The changes of beta-adrenergic receptor mRNA expression are associated with the severity of heart failure.