Metabolic engineering of Escherichia coli for the production of 5-aminolevulinic acid based on combined metabolic pathway modification and reporter-guided mutant selection (RGMS).

Background: 5-Aminolevulinic acid (ALA) recently received much attention due to its potential application in many fields such as medicine, nutrition and agriculture. Metabolic engineering is an efficient strategy to improve microbial production of 5-ALA.

Results: In this study, an ALA production strain of Escherichia coli was constructed by rational metabolic engineering and stepwise improvement.

and degradation, biocompatibility and bone repair performance of strontium-doped montmorillonite coating on Mg-Ca alloy.

Poor bone growth remains a challenge for degradable bone implants. Montmorillonite and strontium were selected as the carrier and bone growth promoting elements to prepare strontium-doped montmorillonite coating on Mg-Ca alloy. The surface morphology and composition were characterized by SEM, EDS, XPS, FT-IR and XRD.

Securin acetylation prevents precocious separase activation and premature sister chromatid separation.

Lysine acetylation of non-histone proteins plays crucial roles in many cellular processes. In this study, we examine the role of lysine acetylation during sister chromatid separation in mitosis. We investigate the acetylation of securin at K21 by cell-cycle-dependent acetylome analysis and uncover its role in separase-triggered chromosome segregation during mitosis.

Advances in functional coatings on biliary stents.

Biliary stenting is an important interventional method for the prevention and treatment of biliary tract diseases. However, complications, such as postoperative biliary infection and restenosis, frequently occur due to the extensive scope of the biliary system and the complex composition of bile. The combination of coating technology and biliary stents is expected to bring new approaches to the solution of these problems.

Copolymers functionalized with quaternary ammonium compounds under template chain exhibit simultaneously efficient bactericidal and flocculation properties: Characterization, performance and mechanism.

In this work, novel multifunctional cationic template copolymers with flocculation and sterilization capabilities were synthesized using a low-pressure ultraviolet (LP-UV) template polymerization method for the removal of kaolin and Escherichia coli (E. coli) from water. The influence of template agents on the structural performance of the copolymers was evaluated through characterization, which showed that template copolymer TPADM possesses a higher cationic charge density and a more complex rough surface, contributing to better flocculation performance than that of the non-template copolymer CPADM.

Antibacterial Activity and Biocompatibility of Ag-Montmorillonite/Chitosan Colloidal Dressing in a Skin Infection Rat Model: An In Vitro and In Vivo Study.

(1) Background: Traditional dressings can only superficially cover the wound, they have widespread issues with inadequate bacterial isolation and liquid absorption, and it is simple to inflict secondary wound injury when changing dressings. Therefore, it is crucial for wound healing to develop a new kind of antimicrobial colloidal dressing with good antibacterial, hygroscopic, and biocompatible qualities. (2) Methods: Ag-montmorillonite/chitosan (Ag-MMT/CS) colloid, a new type of antibacterial material, was prepared from two eco-friendly materials-namely, montmorillonite and chitosan-as auxiliary materials, wherein these materials were mixed with the natural metal Ag, which is an antibacterial agent.

degradation, photo-dynamic and thermal antibacterial activities of Cu-bearing chlorophyllin-induced Ca-P coating on magnesium alloy AZ31.

Surgical failures, caused by postoperative infections of bone implants, are commonly met, which cannot be treated precisely with intravenous antibiotics. Photothermal therapy (PTT) and photodynamic therapy (PDT) have attracted widespread attention due to their non-invasive antibacterial effects on tissues and no bacterial resistance, which may be an excellent approach to solve infections related to bone implants for biodegradable magnesium alloys. Herein, a sodium copper chlorophyllin (SCC) with a porphyrin ring induced Ca-P coating was prepared on AZ31 magnesium alloy via layer-by-layer (LbL) assembly.

CCDC84 Acetylation Oscillation Regulates Centrosome Duplication by Modulating HsSAS-6 Degradation.

In animal cells, centriole number is strictly controlled in order to guarantee faithful cell division and genetic stability, but the mechanism by which the accuracy of centrosome duplication is maintained is not fully understood. Here, we show that CCDC84 constrains centriole number by modulating APC/C-mediated HsSAS-6 degradation. More importantly, CCDC84 acetylation oscillates throughout the cell cycle, and the acetylation state of CCDC84 at lysine 31 is regulated by the deacetylase SIRT1 and the acetyltransferase NAT10.

Corrosion resistance and antibacterial activity of zinc-loaded montmorillonite coatings on biodegradable magnesium alloy AZ31.

A Zinc-loaded montmorillonite (Zn-MMT) coating was hydrothermally prepared using Zn ion intercalated sodium montmorillonite (Na-MMT) upon magnesium (Mg) alloy AZ31 as bone repairing materials. Biodegradation rate of the Mg-based materials was studied via potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and hydrogen evolution tests. Results revealed that both Na-MMT and Zn-MMT coatings exhibited better corrosion resistance in Dulbecco's modified eagle medium (DMEM) + 10% calf serum (CS) than bare Mg alloy AZ31 counterparts.

β‑glucan, a dectin‑1 ligand, promotes macrophage M1 polarization via NF‑κB/autophagy pathway.

Pro‑inflammatory (M1) macrophages have key roles in atherogenesis. As β‑glucan has been demonstrated to exert pro‑inflammatory effects, the present study examined whether β‑glucan exerts atherogenic effects via converting macrophages into M1 phenotype. The results from reverse transcription‑quantitative polymerase chain reaction, flow cytometry, western blotting and transmission electron microscope indicated that M1 macrophage markers inducible nitric oxide synthase and cluster of differentiation 80 were upregulated, dectin‑1 (a receptor for β‑glucan) expression and nuclear factor (NF)‑κB nuclear translocation were promoted, and autophagy level was inhibited following β‑glucan treatment of macrophages.

Corrosion resistance of a novel SnO-doped dicalcium phosphate coating on AZ31 magnesium alloy.

A SnO-doped dicalcium phosphate coating was prepared on AZ31 alloy by means of hydrothermal deposition. The results showed that the coating possessed a globular morphology with a long lamellar crystalline structure and a thickness of approximately 40 μm. The surface of the coating became smooth with an increase additive amount of the SnO nanoparticles.

In Vitro Degradation of Pure Magnesium-The Effects of Glucose and/or Amino Acid.

The influences of glucose and amino acid (L-cysteine) on the degradation of pure magnesium have been investigated using SEM, XRD, Fourier transformed infrared (FTIR), X-ray photoelectron spectroscopy (XPS), polarization and electrochemical impedance spectroscopy and immersion tests. The results demonstrate that both amino acid and glucose inhibit the corrosion of pure magnesium in saline solution, whereas the presence of both amino acid and glucose accelerates the corrosion rate of pure magnesium. This may be due to the formation of -C=N- bonding (a functional group of Schiff bases) between amino acid and glucose, which restricts the formation of the protective Mg(OH)₂ precipitates.

Nuclear Factor Erythroid 2-Related Factor 2 Deficiency Results in Amplification of the Liver Fat-Lowering Effect of Estrogen.

Transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) regulates multiple biologic processes, including hepatic lipid metabolism. Estrogen exerts actions affecting energy homeostasis, including a liver fat-lowering effect. Increasing evidence indicates the crosstalk between these two molecules.

Metabolic derivatives of alcohol and the molecular culprits of fibro-hepatocarcinogenesis: Allies or enemies?

Chronic intake of alcohol undoubtedly overwhelms the structural and functional capacity of the liver by initiating complex pathological events characterized by steatosis, steatohepatitis, hepatic fibrosis and cirrhosis. Subsequently, these initial pathological events are sustained and ushered into a more complex and progressive liver disease, increasing the risk of fibro-hepatocarcinogenesis. These coordinated pathological events mainly result from buildup of toxic metabolic derivatives of alcohol including but not limited to acetaldehyde (AA), malondialdehyde (MDA), CYP2E1-generated reactive oxygen species, alcohol-induced gut-derived lipopolysaccharide, AA/MDA protein and DNA adducts.

Nrf2 is essential for timely M phase entry of replicating hepatocytes during liver regeneration.

The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) regulates various cellular activities, including redox balance, detoxification, metabolism, autophagy, proliferation, and apoptosis. Several studies have demonstrated that Nrf2 regulates hepatocyte proliferation during liver regeneration. The aim of this study was to investigate how Nrf2 modulates the cell cycle of replicating hepatocytes in regenerating livers.

Keap1 modulates the redox cycle and hepatocyte cell cycle in regenerating liver.

Keap1 negatively controls the activity of transcription factor Nrf2. This Keap1/Nrf2 pathway plays a critical role in combating oxidative stress. We aimed at determining whether and how Keap1 modulates the cell cycle of replicating hepatocytes during liver regeneration.

Nrf2 participates in regulating maternal hepatic adaptations to pregnancy.

Pregnancy induces widespread adaptive responses in maternal organ systems including the liver. The maternal liver exhibits significant growth by increasing the number and size of hepatocytes, by largely unknown mechanisms. Nrf2 mediates cellular defense against oxidative stress and inflammation and also regulates liver regeneration.

Proteomic analysis of immediate-early response plasma proteins after 70% and 90% partial hepatectomy.

Aim: Partial hepatectomy (PH) induces robust hepatic regenerative and metabolic responses that are considered to be triggered by humoral factors. The aim of the study was to identify plasma protein factors that potentially trigger or reflect the body's immediate-early responses to liver mass reduction.

Methods: Male C57BL/6 mice were subjected to sham operation, 70% PH or 90% PH.

Protective effects of tiopronin against high fat diet-induced non-alcoholic steatohepatitis in rats.

Aim: To study the protective effects of tiopronin against high fat diet-induced non-alcoholic steatohepatitis in rats.

Methods: Male Sprague-Dawley rats were given a high-fat diet for 10 weeks. The rats were administered tiopronin (20 mg/kg) or a positive control drug ursodeoxycholic acid (UDCA, 15 mg/kg) via gavage daily from week 5 to week 10.

Four waves of hepatocyte proliferation linked with three waves of hepatic fat accumulation during partial hepatectomy-induced liver regeneration.

Unlabelled: Partial hepatectomy (PH) triggers hepatocyte proliferation-mediated liver repair and is widely used to study the mechanisms governing liver regeneration in mice. However, the dynamics of the hepatocyte proliferative response to PH remain unclear. We found that PH-induced mouse liver regrowth was driven by four consecutive waves of hepatocyte replication.

Maternal hepatic growth response to pregnancy in the mouse.

Pregnancy is characterized by physiological adjustments in the maternal compartment. In this investigation, the influence of pregnancy on maternal liver was examined in CD-1 mice. Dramatic changes were observed in the size of the maternal liver during pregnancy.