Purinoceptors, renal microvascular function and hypertension

Proper renal blood flow (RBF) and glomerular filtration rate (GFR) are critical for maintaining normal blood pressure, kidney function and water and electrolyte homeostasis. The renal microvasculature expresses a multitude of receptors mediating vasodilation and vasoconstriction, which can influence glomerular blood flow and capillary pressure. Despite this, RBF and GFR remain quite stable when arterial pressure fluctuates because of the autoregulatory mechanism. ATP and adenosine participate in autoregulatory control of RBF and GFR via activation of two different purinoceptor families (P1 and P2). Purinoceptors are widely expressed in renal microvasculature and tubules. Emerging data show altered purinoceptor signaling in hypertension-associated kidney injury, diabetic nephropathy, sepsis, ischemia-reperfusion induced acute kidney injury and polycystic kidney disease. In this brief review, we highlight recent studies and new insights on purinoceptors regulating renal microvascular function and renal hemodynamics. We also address the mechanisms underlying renal microvascular injury and impaired renal autoregulation, focusing on purinoceptor signaling and hypertension-induced renal microvascular dysfunction. Interested readers are directed to several excellent and comprehensive reviews that recently covered the topics of renal autoregulation, and nucleotides in kidney function under physiological and pathophysiological conditions (Inscho 2009, Navar et al. 2008, Carlstrom et al. 2015, Vallon et al. 2020).

Characterization of a robust cold-adapted and thermostable laccase from Pycnoporus sp. SYBC-L10 with a strong ability for the degradation of tetracycline and oxytetracycline by laccase-mediated oxidation

A native laccase (Lac-Q) with robust cold-adapted and thermostable characteristics from the white-rot fungus Pycnoporus sp. SYBC-L10 was purified, characterized, and used in antibiotic treatments. Degradation experiments revealed that Lac-Q at 10.0 U mL^-1 coupled with 1.0 mmol L^-1 ABTS could degrade 100% of the tetracycline or oxytetracycline (50 mg L^-1) within 5 min with a static incubation at 0 °C (pH 6.0). The presence of the Mn²⁺ ion inhibited the removal rate of tetracycline and oxytetracycline by the Lac-Q-ABTS system, and the presence of Al³⁺, Cu²⁺, and Fe³⁺ accelerated the removal rate of tetracycline and oxytetracycline by the Lac-Q-ABTS system. Furthermore, the growth inhibition of Bacillus altitudinis SYBC hb4 and E. coli by tetracycline antibiotics revealed that the antimicrobial activity was significantly reduced after treatment with the Lac-Q-ABTS system. Finally, seven transformation products of oxytetracycline (namely TP 445, TP 431, TP 413, TP 399, TP 381, TP 367, and TP 351) were identified during the Lac-Q-mediated oxidation process by using UPLC-MS/MS. A possible degradation pathway including deamination, demethylation, and dehydration was proposed. These results suggest that the Lac-Q-ABTS system shows a great potential for the treatment of antibiotic wastewater containing different metal ions at various temperatures.

First-principles investigation of nonmetal doped single-layer BiOBr as a potential photocatalyst with a low recombination rate

Nonmetal doping is an effective approach to modify the electronic band structure and enhance the photocatalytic performance of bismuth oxyhalides.

Functional expression of the Spodoptera exigua chitinase to examine the virtually screened inhibitor candidates

Chitinase is responsible for insect chitin hydrolyzation, which is a key process in insect molting and pupation. However, little is known about the chitinase of Spodoptera exigua (SeChi). In this study, based on the SeChi gene (ADI24346) identified in our laboratory, we constructed the recombinant baculovirus P-Chi for the expression of recombinant SeChi (rSeChi) in Hi5 cells. The rSeChi was purified by chelate affinity chromatography, and the purified protein showed activity comparable with that of a commercial SgChi, suggesting that we harvested active SeChi for the first time. The purified protein was subsequently tested for enzymatic properties and revealed to exhibit its highest activity at pH 8 and 40 C. Using homology modeling and molecular docking techniques, the three-dimensional model of SeChi was constructed and screened for inhibitors. In two rounds of screening, twenty compounds were selected. With the purified rSeChi, we tested each of the twenty compounds for inhibitor activity against rSeChi, and seven compounds showed obvious activity. This study provided new information for the chitinase of beet armyworm and for chitinase inhibitor development.

Evaluation of the Strain Bacillus amyloliquefaciens YP6 in Phoxim Degradation via Transcriptomic Data and Product Analysis

Phoxim, a type of organophosphorus pesticide (OP), is widely used in both agriculture and fisheries. The persistence of phoxim has caused serious environmental pollution problems. In this study, Bacillus amyloliquefaciens YP6 (YP6), which is capable of promoting plant growth and degrading broad-spectrum OPs, was used to study phoxim degradation. Different culture media were applied to evaluate the growth and phoxim degradation of YP6. YP6 can grow rapidly and degrade phoxim efficiently in Luria-Bertani broth (LB broth) medium. Furthermore, it can also utilize phoxim as the sole phosphorus source in a mineral salt medium. Response surface methodology was performed to optimize the degradation conditions of phoxim by YP6 in LB broth medium. The optimum biodegradation conditions were 40 °C, pH 7.20, and an inoculum size of 4.17% (v/v). The phoxim metabolites, O,O-diethylthiophosphoric ester, phoxom, and α-cyanobenzylideneaminooxy phosphonic acid, were confirmed by liquid chromatography-mass spectrometry. Meanwhile, transcriptome analysis and qRT-PCR were performed to give insight into the phoxim-stress response at the transcriptome level. The hydrolase-, oxidase-, and NADPH-cytochrome P450 reductase-encoding genes were significantly upregulated for phoxim hydrolysis, sulfoxidation, and o-dealkylation. Furthermore, the phoxim biodegradation pathways by YP6 were proposed, for the first time, based on transcriptomic data and product analysis.

Mir-138-5p acts as a tumor suppressor by targeting pyruvate dehydrogenase kinase 1 in human retinoblastoma

OBJECTIVE

MicroRNAs have caught more attention for their role in tumor progression. Retinoblastoma (RB) is one of these ordinary malignant tumors. This study aims to identify whether mir-138-5p can regulate the development of RB, and find out its potential mechanism.

MATERIALS AND METHODS

Mir-138-5p expression in RB cells was monitored by RT-qPCR. Besides, the role of mir-138-5p in RB development was explored through function experiments in vitro. The potential mechanism was further explored by RT-qPCR, luciferase assay, and Western blot assay.

RESULTS

In our investigation, mir-138-5p was lower-expressed in RB cells than that in retinal pigment epithelial cells. Moreover, overexpression of mir-138-5p repressed cell viability, migration and invasion, and induced apoptosis of RB cells, while downregulated mir-138-5p increased cell viability, migration and invasion, and reduced apoptosis of RB cells. Furthermore, pyruvate dehydrogenase kinase 1 (PDK1) could be downregulated via overexpression of mir-138-5p, while PDK1 was upregulated via knockdown of mir-138-5p.

CONCLUSIONS

Our results suggested that mir-138-5p could repress the development of RB via suppressing PDK1, which may offer a new vision for interpreting the mechanism of RB tumorigenesis.

ZB transposon and chicken vasa homologue (Cvh) promoter interact to increase transfection efficiency of primordial germ cells in vivo

1. In order to increase the efficiency of generating transgenic chicken, this trial focused on two points: primordial germ cells (PGCs）transfection in vivo and a germline-specific promoter.2. In order to transfect PGCs in vivo, two plasmids (pZB-CAG-GFP, pCMV-ZB）were co-injected into chicken embryos via the subgerminal cavity at Hamburger and Hamilton (HH) stage 2-3 or via blood vessel at HH stage 13-14. Results showed that the percentage of GFP+ embryos, viability and hatching rate of embryos injected at HH stage 13-14 were significantly higher than that at HH stage 2-3.3. Two plasmid transposon systems were used for chicken embryo micro-injections. The donor plasmid, with a green fluorescent protein (GFP) reporter gene, was mediated by the ZB transposon. The helper plasmid was a transposase expression vector driven by the promoter of the chicken vasa homologue (Cvh) gene or Human cytomegalovirus (CMV) promoter. Results showed that 60.98% of gonads in Cvh group expressed GFP, which was 52.50% higher than seen in the CMV group. Only gonad tissue from the Cvh group showed any GFP signal, whereas both gonads and other tissues in the CMV group showed green fluorescence.4. The data suggested that ZB transposon-mediated gene transfer was efficient for transfecting PGCs in vivo; the Cvh promoter drove the transposase gene specifically in the germline and increased the efficiency of germline transmission. Blood vessels injection at HH stage 13-14 may be a more efficient route for PGCs transfection in vivo.

The effects of phytoremediation on soil bacterial communities in an abandoned mine site of rare earth elements

Overexploitation of rare earth elements (REEs) has caused serious desertification and environmental pollution. The ecological restoration of mining areas has attracted increasing attention in China. Soil microbiota is important for successful ecological remediation of abandoned mine land. In this study, soil samples were collected from a restored REE mine site, and the bacterial community composition and diversity were assessed by Illumina high-throughput sequencing targeting the V3-V4 region of the 16S rRNA gene. Microbiota significantly developed in the remediated land. A total of 663,781 effective 16S rRNA gene sequences were obtained, which were classified into 28 bacterial phyla and 3 archaeal phyla. The dominant phyla across all samples (>5% of total effective sequences) were Proteobacteria, Acidobacteria and Firmicutes. Bacterial diversity indices (OTU number, Shannon index and Chao1 index) of the restored soils were higher than those of the tailings and even surpassed those in the unmined site. Redundancy analysis indicated that soil nutrients (soil organic carbon, available phosphorus and total nitrogen) were the dominant factors, followed by soil pH, affecting bacterial community structure. In general, these results suggested that soil amendment and phytoremediation effectively improved the soil environment of the abandoned mine site, which also increased our understanding of the correlation between microbial variation and soil properties in restored REE mine soils.

An alkaline phosphatase from Bacillus amyloliquefaciens YP6 of new application in biodegradation of five broad-spectrum organophosphorus pesticides

In recent decades, biodegradation has been considered a promising and eco-friendly way to eliminate organophosphorus pesticides (OPs) from the environment. To enrich current biodegrading-enzyme resources, an alkaline phosphatase (AP3) from Bacillus amyloliquefaciens YP6 was characterized and utilized to test the potential for new applications in the biodegradation of five broad-spectrum OPs. Characterization of AP3 demonstrated that activity was optimal at 40 °C and pH 10.3. The activity of AP3 was enhanced by Mg²⁺, Ca²⁺, and Cu²⁺, and strongly inhibited by Mn²⁺, EDTA, and L-Cys. Compared to disodium phenyl phosphate, p-nitrophenyl phosphate (pNPP) was more suitable to AP3, and the V_m, K_m, k_cat, k_cat/K_m values of AP3 for pNPP were 4,033 U mg^-1, 12.2 mmol L^-1, 3.3 × 10⁶ s^-1, and 2.7 × 10⁸ s^-1mol^-1L, respectively. Degradation of the five OPs, which included chlorpyrifos, dichlorvos, dipterex, phoxim, and triazophos, was 18.7%, 53.0%, 5.5%, 68.3%, and 96.3%, respectively, after treatment with AP3 for 1 h. After treatment of the OP for 8 h, AP3 activities remained more than 80%, with the exception of phoxim. It can be postulated that AP3 may have a broad OP-degradation ability and could possibly provide excellent potential for biodegradation and bioremediation in polluted ecosystems.

Mining of aminotransferase gene ota3 from Bacillus pumilus W3 via genome analysis, gene cloning and expressing for compound bioamination

Aminotransferases are widely employed as biocatalysts to produce chiral amines and biologically active pharmaceuticals via asymmetric synthesis. In this study, transaminase genes in the Bacillus pumilus W3 genome were analysed, and gene ota3 encoding a putative (R)-selective transaminase was identified. The sequence of ota3 shares highest sequence identity (24.7%) with the first (R)-selective aminotransferase from Arthrobacter sp. KNK 168. Amino acid sequence and conserved domains analyses indicated that ω-BPAT encoded by ota3 belonged to the pyridoxal 5'-phosphate-dependent class IV (PLPDE_IV) superfamily. Both native and codon-optimised ω-BPAT genes were recombinantly expressed, and the purified proteins had a molecular mass of ~33.4 kDa. Furthermore, enantioselectivity tests with (S)- and (R)-α-phenethylamine revealed its (R)-selectivity. The optimal conditions for catalytic reaction were 45 °C and pH 7.0, and ω-BPAT retained stability at 20 °C and pH 7.0. Thus, ω-BPAT is a novel (R)-selective aminotransferase with great potential as a universal biocatalyst.

[Retinal image quality in northern rural Chinese adult population]

Objective: To assess the retinal image quality of the normal northern rural Chinese adult population. Methods: A normal population-based, cross-sectional study. From Oct, 2012 to Jan 2013, a clustered, random sampling procedure was used to select normal population who visual acuity≤ 0(LogMAR) and 30-69 years old from 2 villages. All eligible subjects were invited to undergo a comprehensive eye examination, and the retinal image quality related index were examined with pupil 4 mm using objective optical quality analysis systemⅡ(OQAS Ⅱ, Visiometrics, Spain), including MTFcutoff, VA20, VA9, PSF50, PSF10, OSI, SR. And describe the retinal image quality of different age group, including 30-39y, 40-49y, 50-59y, 60-69y. Results: Among 1 108 participants (61.9%) that completed examinations in our center, 681 participants (1 362 eyes) were recruited. There were 146, 586, 440 and 190 eyes in each group. The spherical equivalent refraction of each group was (-0.35±0.84), (-0.19±0.50), (-0.03±0.54) and (0.20±0.71) D. The best corrected vision acuity of each group was -0.02±0.04, -0.01±0.03, -0.01±0.02 and -0.00±0.01. The MTFcutoff of each group was (37.06±9.31), (36.69±8.93), (36.52±9.05) and (32.61±10.08) c/deg. Retinal imaging parameters were significantly different(MTFcutoff: MD=4.45, SR:MD=0.03, PSF50: MD=-0.45, PSF10: MD=-2.87, VA20:MD=0.13, A9:MD=0.09, OSI:MD=-0.41, P<0.001)between aged 30-39 group and aged 60-69 group. Objective scattering index (OSI) were significantly different(MD=-0.13, P=0.004)between aged 30-39 group and aged 50-59 group. Retinal imaging parameters were significantly different(MTFcutoff:MD=4.45, SR:MD=0.03, PSF50:MD=-0.45, PSF10:MD=-2.87, VA20:MD=0.13, VA9: MD=0.09, OSI: MD=-0.41, P<0.001)between aged 40-49 group and aged 60-69 group. Retinal imageing parameters were significantly different(MTFcutoff: MD=4.45, SR: MD=0.03, PSF50: MD=-0.45, PSF10: MD=-2.87, VA20:MD=0.13, VA9:MD=0.09, OSI:MD=-0.41,P<0.001)between aged 50-59 group and aged 60-69 group. Conclusion: Retinal image quality was gradually worse over time in the northern rural Chinese adult population. (Chin J Ophthalmol, 2018, 54:593-598).