Lipid accumulation and SNF1 transcriptional analysis of Mucor circinelloides on xylose under nitrogen limitation.

Sucrose non-fermenting 1 (SNF1) plays a crucial role in utilizing non-glucose carbon sources and regulating lipid metabolism. However, the mechanism by which SNF1 regulates lipid accumulation in oleaginous filamentous fungi in response to nutrient signals remains unclear. In the present study, by analysing the growth and lipid accumulation of M. circinelloides on xylose under nitrogen limitation, combined with the transcriptional changes of each subunit of SNF1, the regulation of SNF1 between nutrient signal and lipid accumulation was explored. The results showed that with the increase of carbon/nitrogen (C/N) ratio, the xylose consumption and cell growth of M. circinelloides decreased, and the lipid accumulation increased gradually. The optimal C/N ratio was 160:1, and the maximum lipid yield was 4.1 g/L. Two subunits of SNF1, Snf-α1 and Snf-ß, are related to the regulation of lipid metabolism in response to nutrient signals from different external nitrogen sources. This is the first report on the transcriptional analysis of SNF1 subunits on xylose metabolism under nitrogen limitation. This study provides a basis for further understanding of lipid synthesis mechanism on xylose in oleaginous fungi, and it also lays a foundation for the genetic engineering of high-lipid strain.

Effect of Different Carbons on Lipid Production and SNF1 Transcription in Mucor Circinelloides.

Sucrose non-fermenting 1 (SNF1) protein kinase plays an important role in the utilization of selective carbon sources and regulation of lipid metabolism. In order to further explore the function of SNF1 in regulating lipid accumulation by responding nutritional signals from non-glucose carbon sources, in the present study, the lipid production and SNF1 transcriptional levels of Mucor circinelloides were analyzed and compared on different carbon sources. The results indicated that M. circinelloides could effectively utilize some secondary metabolic carbon sources of monosaccharides and disaccharides for growth and lipids production, such as fructose, maltose and galactose. Snf-ß subunit was associated with the regulation of lipid metabolism in response to nutritional signals from different carbon sources. This is the first report on the transcriptional analysis of SNF1 subunits on different carbons metabolism in oleaginous filamentous fungi. This research has suggested that genetic engineering of SNF1 subunits will alter the lipid production of M. circinelloides from alternative carbon sources. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01070-z.

Ryk receptors on unmyelinated nerve fibers mediate excitatory synaptic transmission and CCL2 release during neuropathic pain induced by peripheral nerve injury.

Background Neuropathic pain is a major pathology of the central nervous system associated with neuroinflammation. Ryk (receptor-like tyrosine kinase) receptors act as repulsive axon-guidance molecules during development of central nervous system and neural injury. Increasing evidence suggests the potential involvement of Wnt/Ryk (wingless and Int) signaling in the pathogenesis of neuropathic pain. However, its underlying mechanism remains unknown. Results The expression and location of Ryk receptor as well as its ligand Wnt1 were detected by qPCR, Western blot, and immunohistochemistry. We found that Ryk, a specific Wnt receptor, was expressed in IB4+ (Isolectin B4) and CGRP+ (calcitonin gene-related peptide) dorsal root ganglia neurons and their ascending unmyelinated fibers in the dorsal horn of the spinal cord. Ryk was upregulated after spinal nerve ligation surgery. Wnt1 was also increased in activated astrocytes in the dorsal horn after spinal nerve ligation. The presynaptic mechanism of Ryk in regulation of neuropathic pain was determined by electrophysiology in spinal slice. Spinal nerve ligation model was established, and the therapeutic potential of inhibiting Ryk receptor was determined. Spine-specific blocking of the Wnt/Ryk receptor signaling attenuated the spinal nerve ligation-induced mechanical allodynia but not thermal hyperalgesia. Further, it also blocked Ca2+-dependent signals including CaMKII and PKCγ, subsequent release of CCL2 (CCR-like protein) in the dorsal horn. An in vitro study showed that inactivating Ryk receptors with anti-Ryk antibodies or lentiviral Ryk shRNA led to the inactivation of Wnt1 for excitatory synaptic transmission in spinal slices and subsequent decrease in CCL2 expression in the dorsal root ganglia neurons. Conclusion These studies demonstrate the existence of critical crosstalk between astrocytes and unmyelinated fibers, which indicate the presynaptic mechanism of Ryk in cytokine transmission of neuropathic pain and the therapeutic potential for Wnt/Ryk signaling pathway in the treatment of neuropathic pain.

Parthenolide Induces Reactive Oxygen Species-Mediated Autophagic Cell Death in Human Osteosarcoma Cells.

BACKGROUND AND AIM: Osteosarcoma is a devastating tumor of bone, primarily affecting adolescents. Parthenolide, a naturally occurring small molecule that interferes with NF-κB signaling, has recently attracted considerable attention because of its pharmacological action involving anti-cancer effects. However, the mechanism of the cytotoxic effect exerted by parthenolide on tumor cells is not clearly defined today. METHODS: In this study, the effects of parthenolide were evaluated and characterized in human osteosarcoma cancer cell. Cell viability was assessed by CCK-8. Apoptosis was assessed by Annexin V-FITC/PI Flow cytometry assay. Relative quantitative real-time PCR and western blot were used to determine the expressions of genes and proteins. RESULTS: Our results suggest that parthenolide did not cause caspase-dependent cell death in osteosarcoma cancer cells, as indicated by the absence of significant early apoptosis as well as caspase-3 cleavage. Instead, parthenolide increased the autophagy and mitophagy, as characterized by increased PINK1 and Parkin translocation to mitochondria and enhanced autophagy proteins. The induction of autophagy by parthenolide was associated with the increase of reactive oxygen species (ROS). ROS antioxidants N-acetylcysteine (NAC) attenuated parthenolide-induced autophagy activity. CONCLUSIONS: Our findings unveil a novel mechanism of drug action by parthenolide in osteosarcoma cancer cells and suggest a potential value of treating osteosarcoma cancer through a caspase-independent autophagic cell death by ROS activation.

Knockout of TRPV6 causes osteopenia in mice by increasing osteoclastic differentiation and activity.

BACKGROUND: Calcium ion (Ca(2+)) signals are required for osteoclast differentiation. Previous study showed that transient receptor potential vanilloid 5 (TRPV5) is an essential Ca(2+) transporter in osteoclastogenesis and bone resorption. TRPV5 and TRPV6 represent two highly homologous members within the transient receptor potential (TRP) superfamily. However, the role of TRPV6 in bone metabolism is still controversial and little is known about the involvement of TRPV6 in receptor activator of nuclear factor κ-B ligand (RANKL)-induced osteoclastogenesis. METHODS: In our study, gene knockout mice, RNA interference, western blot, quantitative real-time PCR, tartrate-resistant acid phosphatase (TRAP) staining, pit formation assay, histomorphometry and measurement of serum parameters were employed to investigate the role of TRPV6 in bone homeostasis, osteoclastogenesis and bone resorption. RESULTS: We found that TRPV6 depletion results in noticeable destruction of bone microarchitecture in TRPV6 knockout mice (TRPV6(-/-)), suggesting that TRPV6 is a critical regulator in bone homeostasis. Inactivation of Trpv6 had no effect on osteoblastic bone formation. However, quantification of the TRAP staining showed a significantly increased osteoclast number and surface area in the metaphyseal area of femurs bone sections derived from TRPV6(-/-) mice. In agreement with our observations from TRPV6(-/-) mice, TRPV6 depletion in vitro significantly increased osteoclasts differentiation and bone resorption activity. CONCLUSION: Based on these results above, we can draw conclusions that TRPV6 plays an essential role in bone metabolism and is a critical regulator in osteoclasts differentiation and bone resorption.

Lipid Accumulation by Snf-ß Engineered Mucor circinelloides Strains on Glucose and Xylose.

Sucrose non-fermenting 1 (SNF1) protein kinase plays the regulatory roles in the utilization of selective carbon sources and lipid metabolism. Previously, the role of ß subunit of SNF1 in lipid accumulation was evaluated by overexpression and knockout of Snf-ß in oleaginous fungus M. circinelloides. In the present study, the growth and lipid accumulation of Snf-ß overexpression and knockout strains were further analyzed and compared with glucose or xylose as a single or mixed carbon sources. The results showed that the lipid contents in Snf-ß knockout strain improved by 23.2% (for glucose), 28.4% (for xylose), and 30.5% (for mixed glucose and xylose) compared with that of the control strain, respectively. The deletion of Snf-ß subunit also altered the transcriptional level of acetyl-CoA carboxylase (ACC). The highest transcriptional levels of ACC1 in Snf-ß knockout strain at 24 h were increased by 2.4-fold (for glucose), 2.8-fold (for xylose), and 3.1-fold (for mixed glucose and xylose) compared with that of the control strain, respectively. Our results indicated that Snf-ß subunit enhanced lipid accumulation through the regulation of ACC1 in response to xylose or mixed sugars of glucose and xylose more significantly than that of response to glucose. This is the first study to explore the effect of Snf-ß subunit of M. circinelloides in regulating lipid accumulation responding to different carbon nutrient signals of glucose and xylose. This study provides a foundation for the future application of the Snf-ß engineered strains in lipid production from lignocellulose.

A smart pathogen detector engineered from intracellular hydrogelation of DNA-decorated macrophages.

Bacterial infection is a major threat to global public health, which urgently requires useful tools to rapidly analyze pathogens in the early stages of infection. Herein, we develop a smart macrophage (Mø)-based bacteria detector, which can recognize, capture, enrich and detect different bacteria and their secreted exotoxins. We transform the fragile native Møs into robust gelated cell particles (GMøs) using photo-activated crosslinking chemistry, which retains membrane integrity and recognition capacity for different microbes. Meanwhile, these GMøs equipped with magnetic nanoparticles and DNA sensing elements can not only respond to an external magnet for facile bacteria collection, but allow the detection of multiple types of bacteria in a single assay. Additionally, we design a propidium iodide-based staining assay to rapidly detect pathogen-associated exotoxins at ultralow concentrations. Overall, these nanoengineered cell particles have broad applicability in the analysis of bacteria, and could potentially be used for the management and diagnosis of infectious diseases.

Association of VEGF gene polymorphisms with advanced retinopathy of prematurity: a meta-analysis.

Published data on the association of vascular endothelial growth factor (VEGF) gene polymorphisms with retinopathy of prematurity (ROP) are inconclusive. The aim of the study was to assess the association by using meta-analysis. Data were collected from the following electronic databases: PubMed, Elsevier Science Direct, Excerpta Medica Database, Cochrane Library and China National Knowledge Infrastructure, with the last report up to 30 April, 2012. The odds ratio (OR) and its 95 % confidence interval (95 %CI) were used to assess the strength of the association. Meta-analysis was performed in a fixed/random effect model by using the software Review Manager 4.2. A total of 7 studies based on the search criteria were involved in this meta-analysis. Meta-analysis was performed for four VEGF gene polymorphisms (-634G/C, -460T/C, -2578C/A and 936C/T). Significant association was found for -460T/C polymorphism (C vs T: OR = 0.74, 95 %CI = 0.57-0.95, P = 0.02; TC+CC vs TT: OR = 0.75, 95 %CI = 0.47-1.21, P = 0.24; CC vs TT+TC: OR = 0.45, 95 %CI = 0.26-0.76, P = 0.003; CC vs TT: OR = 0.45, 95 %CI = 0.24-0.84, P = 0.01; TC vs TT: OR = 0.96, 95 %CI = 0.59-1.57, P = 0.87) in the VEGF gene, but not for other polymorphisms (-634G/C, -2578C/A and 936C/T). This meta-analysis demonstrates that advanced ROP is associated with VEGF gene -460T/C polymorphism, but not -634G/C, -2578C/A and 936C/T.

Minimally invasive treatment for Neer IIb distal clavicle fractures with titanium cable.

BACKGROUND: Neer IIB distal clavicle fracture is associated with disruption of the coracoclavicular ligament and a variable degree of displacement. Surgical treatment using various implants such as intramedullary wires, screws, and plates has been described in the literature with satisfactory results. METHODS: We report our experience of minimally invasive treatment using titanium cable for type IIB clavicular fractures. A retrospective analysis was performed to evaluate the outcomes of patients with Neer IIB distal clavicle fractures that were treated with titanium cable between 2003 and 2008. Functional outcome was evaluated using the Karlsson's criteria. The mean follow-up was 32 months (range, 12-48 months). Twenty-nine patients met the inclusion criteria. RESULTS: All patients progressed to osseous union at a mean time of 12 weeks (range, 10-15 weeks). There was one metal work failure that did not affect functional recovery. According to Karlsson's criteria, radiographic representations (3 months after surgery) and postoperative shoulder functional recovery revealed an excellent and good rate in all cases. CONCLUSION: Minimally invasive surgery using titanium cable seems to be a good option for the treatment of Neer IIB distal clavicle fractures, with early functional recovery and no requirement for revision surgery.

A Co-Doped Nanorod-like RuO2 Electrocatalyst with Abundant Oxygen Vacancies for Acidic Water Oxidation.

Active and highly stable electrocatalysts for oxygen evolution reaction (OER) in acidic media are currently in high demand as a cleaner alternative to the combustion of fossil fuels. Herein, we report a Co-doped nanorod-like RuO2 electrocatalyst with an abundance of oxygen vacancies achieved through the facile, one-step annealing of a Ru-exchanged ZIF-67 derivative. The compound exhibits ultra-high OER performance in acidic media, with a low overpotential of 169 mV at 10 mA cm-2 while maintaining excellent activity, even when exposed to a 50-h galvanostatic stability test at a constant current of 10 mA cm-2. The dramatic enhancement in OER performance is mainly attributed to the abundance of oxygen vacancies and modulated electronic structure of the Co-doped RuO2 that rely on a vacancy-related lattice oxygen oxidation mechanism (LOM) rather than adsorbate evolution reaction mechanism (AEM), as revealed and supported by experimental characterizations as well as density functional theory (DFT) calculations.

Effects of Ultraviolet (UV) on Degradation of Irgafos 168 and Migration of Its Degradation Products from Polypropylene Films.

The effects of ultraviolet (UV) irradiation on the degradation of Irgafos 168 and the migration of its two degradation products, 2,4-di-tert-butylphenol and tris(2,4-di-tert-butylphenyl)phosphate, from polypropylene (PP) were investigated. A blown film machine was used to extrude PP films containing Irgafos 168, the films were stored in the dark for 45 days, two UV treatments and sunlight exposure were applied to the films, and GC-MS was used for degradation and migration studies. Extrusion, storage, UV treatments, and sunlight exposure significantly affected concentrations of Irgafos 168 and the degradation products. 2,4-Di-tert-butylphenol was the major degradation product produced by UV irradiation, but tris(2,4-di-tert-butylphenyl)phosphate was the major degradation product produced by extrusion, storage, and sunlight exposure. The degradation products have no or little health risk, because migration study and threshold of toxicological concern (TTC) analysis show that experimental maximum migration of 2,4-di-tert-butylphenol and tris(2,4-di-tert-butylphenyl)phosphate are only 2 and 53% of the theoretical maximum migration amounts, respectively.

Effects of He-Ne laser irradiation on chronic atrophic gastritis in rats.

AIM: To study the effects of He-Ne laser irradiation on experimental chronic atrophic gastritis (CAG) in rats. METHODS: Sixty-three male adult Wistar rats were randomly divided into five groups including normal control group, model control group and three different dosages He-Ne laser groups. The chronic atrophic gastritis (CAG) model in rats was made by pouring medicine which was a kind of mixed liquor including 2% sodium salicylate and 30% alcohol down the throat for 8 wk to stimulate rat gastric mucosa, combining with irregular fasting and compulsive sporting as pathogenic factors; 3.36, 4.80, and 6.24 J/cm(2) doses of He-Ne laser were used, respectively for three different treatment groups, once a day for 20 d. The pH value of diluted gastric acid was determined by acidimeter, the histopathological changes such as the inflammatory degrees in gastric mucosa, the morphology and structure of parietal cells were observed, and the thickness of mucosa was measured by micrometer under optical microscope. RESULTS: In model control group, the secretion of gastric acid was little, pathologic morphological changes in gastric mucosa such as thinner mucous, atrophic glands, notable inflammatory infiltration were found. After 3.36 J/cm(2) dose of He-Ne laser treatment for 20 d, the secretion of gastric acid was increased (P<0.05), the thickness of gastric mucosa was significantly thicker than that in model control group (P<0.01), the gastric mucosal inflammation cells were decreased (P<0.05). Morphology, structure and volume of the parietal cells all recuperated or were closed to normal. CONCLUSION: 3.36 J/cm(2) dose of He-Ne laser has a significant effect on CAG in rats.

[Effects of He-Ne laser on gastric mucosa in rat with chronic atrophic gastritis].

This study sought to explore the effects of He-Ne laser irradiation on the gastric mucosa of experimental chronic atrophic gastritis (CAG) in rat. Fifty-two male adult Wistar rats were randomly divided into five groups including normal control group, model group and three different doses He-Ne laser groups. The CAG model in rats was made by administering (per gastrogavage) a compositus liquor, including 2% sodium salicylate and 30% alcohol, for 8 weeks to stimulate the rat's gastric mucosa, combined with irregular fasting and compulsive sporting as pathogenic factors. He-Ne laser therapy was used at different doses of He-Ne laser, once a day for twenty days, then the morphological changes and the expression of cyclinD1 were observed. Compared with untreated group, the gastric mucosa of 3.36J x cm(-2) He-Ne laser group was significantly thicker (P < 0.01), the inflammatory cells of gastric mucosa were decreased (P < 0.05), the morphology, structure and volume of the cells were restored or nearly normal and the expressions of cyclinD1 were higher (P < 0.05). In a word, small dose He-Ne laser (3.36 J x cm(-2)) has a good adjuvant therapeutic effect on rat's CAG.

CH4 emission and recovery from municipal solid waste in China.

Methane ( CH4) is an important greenhouse gas and a major environmental pollutant, second only to carbon dioxide (CO2) in its contribution to potential global warming. In many cases, methane emission from landfills otherwise emitted to the atmosphere can be removed and utilized, or significantly reduced in quantity by using coat-effective management methods. The gas can also be used as a residential, commercial, or industrial fuel. Therefore, emission reduction strategies have the potential to become low cost, or even profitable. The annual growth rate of Municipal Solid Waste (MSW) output in China is 6.24%, with the highest levels found in South China, Southwest China and East China. Cities and towns are developing quickly in these regions. MSW output was only 76.36 Mt in 1991 and increased to 109.82 Mt in 1997, registering an average increase of 43.8% . In China, methane emission from landfills also increased from 5.88 Mt in 1991 to 8.46 Mt in 1997; so the recovery of methane from landfills is a profitable project.

Treatment of chitin-producing wastewater by micro-electrolysis-contact oxidization.

The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater. Results showed that Fe-C micro-electrolysis can remove about 30% COD(cr), raise pH from 0.7 to 5.5. The COD(cr) removal efficiency by biochemical process can be more than 80%. During a half year's operation, the whole system worked very stably and had good results, as proved by the fact that every quality indicator of effluent met the expected discharge standards; which means that chitin wastewater can be treated by the technique of micro-electrolysis, contact oxidization.

Reduction of hexavalent chromium by carboxymethyl cellulose-stabilized zero-valent iron nanoparticles.

The reduction of hexavalent chromium or Cr(VI) by zero-valent iron (Fe(0)) nanoparticles has received increasing attention in recent years. However, Fe(0) nanoparticles prepared using conventional methods suffered several drawbacks due to their high reactivity towards surrounding media, which led to the formation of much larger flocs and significant loss in reactivity. To overcome these problems, we synthesized Fe(0) nanoparticles by applying water-soluble carboxymethyl cellulose (CMC) as a stabilizer. CMC-stabilized Fe(0) nanoparticles displayed much less agglomeration but greater Cr(VI) reduced power than those prepared without a stabilizer. At a dose of 0.15 g L(-)(1), CMC-stabilized Fe(0) nanoparticles were able to reduce 100% of 10 mg L(-)(1) Cr(VI) in minutes. Several factors that may affect the efficiency of Cr(VI) removal were investigated. These included the concentration of CMC, the concentration of Fe(0) nanoparticles, the initial Cr(VI) concentration, the pH value, the reaction temperature and the concentration of the calcium cation in the reaction mixture. Our study suggested that the introduction of an innocuous stabilizer such as CMC could significantly improve the performance of Fe(0) nanoparticles for environmental remediation applications.

Impacts of morphology and crystallite phases of titanium oxide on the catalytic ozonation of phenol.

TiO(2) nanomaterial is widely used for catalytic ozonation. In the present work, TiO(2) nanostructures with various morphology and crystallite phases were synthesized by a hydrothermal method, followed by calcination using Degussa P25 as precursor. The nanotube, nanorod, and nanowire forms were obtained by varying the hydrothermal temperature, and the anatase/rutile ratios were adjusted by controlling the annealing temperature. The catalytic activity of the samples was evaluated by degradation of phenol in aqueous solution in the presence of ozone. We found that the initial degradation rates (IDR) of phenol were dominated primarily by the surface OH groups. Thus, with the help of transmission electron microscopy (TEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) analyses, the number of surface OH groups per unit area of TiO(2) was correlated with the morphology and crystallite phases. Finally, we conclude that the vast surface area and higher rutile phase ratios are favorable for the catalytic ozonation of phenol and the morphology of TiO(2) had negligible effect in our experiments.

[Ecological control effects of Litchi chinensis-Desmodium intortum complex plant ecosystem on litchi pests].

An investigation on the community structure and dynamics of litchi pests and their natural enemies in constructed Litchi chinensis-Desmodium intortum complex plant ecosystem and single L. chinensis ecosystem showed that the total amount of litchi pests in the complex plant ecosystem was 61.27% of that in the single ecosystem in whole year, and only 50.45% in May, the key time for fruit development, which suggested that there was an interaction between D. intortum and L. chinensis. D. intortum and L. chinensis had a few common pests, but many common natural enemies. D. intortum florescence in winter provided shelter and substitutive food for the natural enemies of pests to survive in the extreme environmental conditions in winter. L. chinensis florescence was on the heel of D. intortum florescence, which provided better conditions for the natural enemies to survive and multiply. During florescence and fruit development stages of L. chinensis (from March to June), the predator/prey ratio in complex plant system was 4.22, 2.34, 2.2 and 20.63 times of that in single plant system in March, April, May and June, respectively, indicating the good control effect on pests of L. chinensis.